diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 1bd6ad7bf4..59957f02db 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1,5 +1,9 @@
 name: Build and Test
 
+permissions:
+  contents: read
+  packages: write
+
 on:
   push: {}
   pull_request: {}
@@ -12,32 +16,46 @@ on:
 
 jobs:
   get-matrix:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     outputs:
-      do-linux: ${{ steps.get-matrix-step.outputs.do-linux }}
+      do-linux: ${{ steps.get-matrix-step.outputs.do_linux }}
       matrix-linux: ${{ steps.get-matrix-step.outputs.linux }}
-      do-macos: ${{ steps.get-matrix-step.outputs.do-macos }}
+      do-macos: ${{ steps.get-matrix-step.outputs.do_macos }}
       matrix-macos: ${{ steps.get-matrix-step.outputs.macos }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - id: files
         if: ${{ github.event_name != 'workflow_dispatch' }}
-        uses: kanaka/get-changed-files@v1
+        uses: kanaka/get-changed-files@v2
+        with:
+          default_base: master
       - id: get-matrix-step
         run: |
           export OVERRIDE_IMPLS="${{ github.event.inputs.impls }}" # "
           echo "OVERRIDE_IMPLS: ${OVERRIDE_IMPLS}"
-          ./get-ci-matrix.py ${{ steps.files.outputs.all }}
+          ./get-ci-matrix.py ${{ steps.files.outputs.all }} > "${GITHUB_OUTPUT}"
 
   linux:
     needs: get-matrix
     if: ${{ needs.get-matrix.outputs.do-linux == 'true' }}
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
       matrix: ${{ fromJson(needs.get-matrix.outputs.matrix-linux) }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # Need full history for voom like versions
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Docker Build/Push
+        run: |
+          export ${{ matrix.IMPL }}
+          ./ci.sh docker-build-push ${IMPL}
       - name: Build
         run: |
           export ${{ matrix.IMPL }}
@@ -55,9 +73,9 @@ jobs:
           export ${{ matrix.IMPL }}
           ./ci.sh perf ${IMPL}
       - name: Archive logs and debug output
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
-          name: logs
+          name: logs.${{ matrix.IMPL }}
           path: |
             *.log
             *.debug
@@ -65,12 +83,12 @@ jobs:
   macos:
     needs: get-matrix
     if: ${{ needs.get-matrix.outputs.do-macos == 'true' }}
-    runs-on: macos-10.15
+    runs-on: macos-12
     strategy:
       fail-fast: false
       matrix: ${{ fromJson(needs.get-matrix.outputs.matrix-macos) }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Build
         run: |
           export ${{ matrix.IMPL }}
@@ -88,9 +106,9 @@ jobs:
           export ${{ matrix.IMPL }}
           ./ci.sh perf ${IMPL}
       - name: Archive logs and debug output
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
-          name: logs
+          name: logs.${{ matrix.IMPL }}
           path: |
             *.log
             *.debug
diff --git a/Makefile b/Makefile
index 7d47ad44fb..ff1cd7a643 100644
--- a/Makefile
+++ b/Makefile
@@ -126,7 +126,7 @@ STEP_TEST_FILES = $(strip $(wildcard \
 
 # DOCKERIZE utility functions
 lc = $(subst A,a,$(subst B,b,$(subst C,c,$(subst D,d,$(subst E,e,$(subst F,f,$(subst G,g,$(subst H,h,$(subst I,i,$(subst J,j,$(subst K,k,$(subst L,l,$(subst M,m,$(subst N,n,$(subst O,o,$(subst P,p,$(subst Q,q,$(subst R,r,$(subst S,s,$(subst T,t,$(subst U,u,$(subst V,v,$(subst W,w,$(subst X,x,$(subst Y,y,$(subst Z,z,$1))))))))))))))))))))))))))
-impl_to_image = kanaka/mal-test-$(call lc,$(1))
+impl_to_image = ghcr.io/kanaka/mal-test-$(call lc,$(1)):$(shell ./voom-like-version.sh impls/$(1)/Dockerfile)
 
 actual_impl = $(if $(filter mal,$(1)),$(patsubst %-mal,%,$(MAL_IMPL)),$(1))
 
@@ -143,7 +143,7 @@ get_build_command = $(strip $(foreach mode,$(1)_MODE, \
       $(if $(strip $($(mode))),-e $(mode)=$($(mode)),) \
       $(if $(filter factor,$(1)),-e FACTOR_ROOTS=$(FACTOR_ROOTS),) \
       $(call impl_to_image,$(1)) \
-      $(MAKE) $(if $(strip $($(mode))),$(mode)=$($(mode)),) \
+      make $(if $(strip $($(mode))),$(mode)=$($(mode)),) \
       ,\
       $(MAKE) $(if $(strip $($(mode))),$(mode)=$($(mode)),) -C impls/$(impl))))
 
diff --git a/README.md b/README.md
index 3fa1c13df2..e58e828921 100644
--- a/README.md
+++ b/README.md
@@ -35,9 +35,8 @@ Here is the final diagram for [step A](process/guide.md#stepA):
 ![stepA_mal architecture](process/stepA_mal.png)
 
 If you are interested in creating a mal implementation (or just
-interested in using mal for something), you are welcome to to join our
-[Discord](https://discord.gg/CKgnNbJBpF) or join #mal on
-[libera.chat](https://libera.chat/). In addition to the [make-a-lisp
+interested in using mal for something) you are welcome to to join our
+[Discord](https://discord.gg/CKgnNbJBpF). In addition to the [make-a-lisp
 process guide](process/guide.md) there is also a [mal/make-a-lisp
 FAQ](docs/FAQ.md) where I attempt to answer some common questions.
 
@@ -1452,7 +1451,7 @@ make "docker-build^IMPL"
 
 
 **Notes**:
-* Docker images are named *"kanaka/mal-test-IMPL"*
+* Docker images are named *"ghcr.io/kanaka/mal-test-IMPL"*
 * JVM-based language implementations (Groovy, Java, Clojure, Scala):
   you will probably need to run this command once manually
   first `make DOCKERIZE=1 "repl^IMPL"` before you can run tests because
diff --git a/ci.sh b/ci.sh
index 400045fbeb..f8c98135f9 100755
--- a/ci.sh
+++ b/ci.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -ex
 
@@ -24,11 +24,30 @@ mode_var=${raw_mode_var/-/__}
 mode_var=${mode_var/./__}
 mode_val=${!mode_var}
 
-MAKE="make ${mode_val:+${mode_var}=${mode_val}}"
-
 log_prefix="${ACTION}${REGRESS:+-regress}-${IMPL}${mode_val:+-${mode_val}}${MAL_IMPL:+-${MAL_IMPL}}"
 TEST_OPTS="${TEST_OPTS} --debug-file ../../${log_prefix}.debug"
 
+step_summary() {
+    echo "${*}"
+    if [ "${GITHUB_STEP_SUMMARY}" ]; then
+        echo "${*}" >> "${GITHUB_STEP_SUMMARY}"
+    fi
+}
+
+img_base="${MAL_IMPL:-${IMPL}}"
+img_impl="${img_base%%-mal}"
+img_name="mal-test-$(echo "${img_impl}" | tr '[:upper:]' '[:lower:]')"
+img_ver=$(./voom-like-version.sh impls/${img_impl}/Dockerfile)
+IMAGE="ghcr.io/kanaka/${img_name}:${img_ver}"
+
+# If NO_DOCKER is blank then run make in a docker image
+MAKE="make ${mode_val:+${mode_var}=${mode_val}}"
+if [ -z "${NO_DOCKER}" ]; then
+    # We could just use make DOCKERIZE=1 instead but that does add
+    # non-trivial startup overhead for each step.
+    MAKE="docker run -i -u $(id -u) -v `pwd`:/mal ${IMAGE} ${MAKE}"
+fi
+
 # Log everything below this point:
 exec &> >(tee ./${log_prefix}.log)
 
@@ -47,17 +66,21 @@ echo "IMPL: ${IMPL}"
 echo "BUILD_IMPL: ${BUILD_IMPL}"
 echo "MAL_IMPL: ${MAL_IMPL}"
 echo "TEST_OPTS: ${TEST_OPTS}"
-
-# If NO_DOCKER is blank then launch use a docker image, otherwise use
-# the Travis/Github Actions image/tools directly.
-if [ -z "${NO_DOCKER}" ]; then
-    img_impl=$(echo "${MAL_IMPL:-${IMPL}}" | tr '[:upper:]' '[:lower:]')
-    # We could just use make DOCKERIZE=1 instead but that does add
-    # non-trivial startup overhead for each step.
-    MAKE="docker run -i -u $(id -u) -v `pwd`:/mal kanaka/mal-test-${img_impl%%-mal} ${MAKE}"
-fi
+echo "IMAGE: ${IMAGE}"
+echo "MAKE: ${MAKE}"
 
 case "${ACTION}" in
+docker-build-push)
+    if ! docker pull ${IMAGE}; then
+        step_summary "${MAL_IMPL:-${IMPL}} - building ${IMAGE}"
+        make "docker-build^${MAL_IMPL:-${IMPL}}"
+        step_summary "${MAL_IMPL:-${IMPL}} - built ${IMAGE}"
+        if [ "${GITHUB_REF}" = "refs/heads/main" ]; then
+            docker push ${IMAGE}
+            step_summary "${MAL_IMPL:-${IMPL}} - pushed ${IMAGE}"
+        fi
+    fi
+    ;;
 build)
     # rpython often fails on step9 in compute_vars_longevity
     # so build step9, then continue with the full build
diff --git a/docs/FAQ.md b/docs/FAQ.md
index 49af1d7eee..b045de0867 100644
--- a/docs/FAQ.md
+++ b/docs/FAQ.md
@@ -154,11 +154,57 @@ into the main repository:
   `time-ms` function which is needed to run the micro-benchmark tests).
 
 * Create a `Dockerfile` in your directory that installs all the
-  packages necessary to build and run your implementation. Refer to other
-  implementations for examples of what the Dockerfile should contain.
-  Build your docker image and tag it `kanaka/mal-test-[IMPL_NAME]`.
-  The top-level Makefile has support for building/testing within
-  docker with the `DOCKERIZE` flag:
+  packages necessary to build and run your implementation. In order to
+  integrate fully with the Github Actions CI workflow, the
+  `Dockerfile` needs to include the following boilerplate (with your
+  name, email, and implementation filled in):
+  ```
+  MAINTAINER Your Name <your@email.com>
+  LABEL org.opencontainers.image.source=https://github.com/kanaka/mal
+  LABEL org.opencontainers.image.description="mal test container: Your_Implementation"
+  ```
+
+  In addition, the docker image should provide python3 (with a python
+  symlink to it) to enable running tests using the image. Here is the
+  typical `Dockerfile` template you should use if your
+  implementation does not require a special base distro:
+
+  ```
+  FROM ubuntu:24.04
+  MAINTAINER Your Name <your@email.com>
+  LABEL org.opencontainers.image.source=https://github.com/kanaka/mal
+  LABEL org.opencontainers.image.description="mal test container: Your_Implementation"
+  ##########################################################
+  # General requirements for testing or common across many
+  # implementations
+  ##########################################################
+
+  RUN apt-get -y update
+
+  # Required for running tests
+  RUN apt-get -y install make python3
+  RUN ln -sf /usr/bin/python3 /usr/bin/python
+
+  # Some typical implementation and test requirements
+  RUN apt-get -y install curl libreadline-dev libedit-dev
+
+  RUN mkdir -p /mal
+  WORKDIR /mal
+
+  ##########################################################
+  # Specific implementation requirements
+  ##########################################################
+
+  ... Your packages ...
+  ```
+
+* Build and tag your docker image. The image tag will have the
+  form `ghcr.io/kanaka/mal-test-[IMPL_NAME]:[VOOM_VERSION]`.
+  ```
+  make "docker-build^[IMPL_NAME]"
+
+* The top-level Makefile has support for building/testing using
+  the docker image with the `DOCKERIZE` flag:
   ```bash
   make DOCKERIZE=1 "test^[IMPL_NAME]"
   make DOCKERIZE=1 MAL_IMPL=[IMPL_NAME] "test^mal"
@@ -170,6 +216,9 @@ into the main repository:
   ./ci.sh test [IMPL_NAME]
   ```
 
+* Push your code to a branch and make sure that the automated Github
+  Actions CI passes for your implementation.
+
 * If you are creating a new implementation for an existing
   implementation (or somebody beats you to the punch while you are
   working on it), there is still a chance I will merge your
diff --git a/get-ci-matrix.py b/get-ci-matrix.py
index debcb172f3..1840df0c42 100755
--- a/get-ci-matrix.py
+++ b/get-ci-matrix.py
@@ -12,6 +12,9 @@
 
 OVERRIDE_IMPLS = os.environ.get('OVERRIDE_IMPLS', '').split()
 
+def eprint(*args, **kwargs):
+    print(*args, file=sys.stderr, **kwargs)
+
 def impl_text(impl):
     s = "IMPL=%s" % impl['IMPL']
     for k, v in impl.items():
@@ -37,11 +40,11 @@ def impl_text(impl):
         do_full = True
 
 
-print("OVERRIDE_IMPLS: %s" % OVERRIDE_IMPLS)
-print("code_changes: %s (%d)" % (code_changes, len(code_changes)))
-print("impl_changes: %s (%d)" % (impl_changes, len(impl_changes)))
-print("run_impls: %s (%d)" % (run_impls, len(run_impls)))
-print("do_full: %s" % do_full)
+eprint("OVERRIDE_IMPLS: %s" % OVERRIDE_IMPLS)
+eprint("code_changes: %s (%d)" % (code_changes, len(code_changes)))
+eprint("impl_changes: %s (%d)" % (impl_changes, len(impl_changes)))
+eprint("run_impls: %s (%d)" % (run_impls, len(run_impls)))
+eprint("do_full: %s" % do_full)
 
 # Load the full implementation description file
 all_impls = yaml.safe_load(open(IMPLS_FILE))
@@ -60,7 +63,7 @@ def impl_text(impl):
     elif do_full:
         targ.append(impl_text(impl))
 
-print("::set-output name=do-linux::%s" % json.dumps(len(linux_impls)>0))
-print("::set-output name=do-macos::%s" % json.dumps(len(macos_impls)>0))
-print("::set-output name=linux::{\"IMPL\":%s}" % json.dumps(linux_impls))
-print("::set-output name=macos::{\"IMPL\":%s}" % json.dumps(macos_impls))
+print("do_linux=%s" % json.dumps(len(linux_impls)>0))
+print("do_macos=%s" % json.dumps(len(macos_impls)>0))
+print("linux={\"IMPL\":%s}" % json.dumps(linux_impls))
+print("macos={\"IMPL\":%s}" % json.dumps(macos_impls))
diff --git a/impls/ada/Dockerfile b/impls/ada/Dockerfile
index 5eb272abe0..392e20fd83 100755
--- a/impls/ada/Dockerfile
+++ b/impls/ada/Dockerfile
@@ -1,5 +1,7 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
+LABEL org.opencontainers.image.source=https://github.com/kanaka/mal
+LABEL org.opencontainers.image.description="mal test container: ada"
 
 ##########################################################
 # General requirements for testing or common across many
diff --git a/impls/awk/Dockerfile b/impls/awk/Dockerfile
index 9d0e12cee1..46b05567a9 100644
--- a/impls/awk/Dockerfile
+++ b/impls/awk/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/bash/Dockerfile b/impls/bash/Dockerfile
index 71720eb5e5..81eba8836a 100644
--- a/impls/bash/Dockerfile
+++ b/impls/bash/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/c.2/Dockerfile b/impls/c.2/Dockerfile
index 79bab2ecad..2795e538d2 100644
--- a/impls/c.2/Dockerfile
+++ b/impls/c.2/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:bionic
+FROM ubuntu:24.04
 MAINTAINER Duncan Watts <fungiblecog@gmail.com>
 
 ##########################################################
@@ -9,10 +9,8 @@ MAINTAINER Duncan Watts <fungiblecog@gmail.com>
 RUN apt-get -y update
 
 # Required for running tests
-RUN apt-get -y install make python
-
-# Some typical implementation and test requirements
-#RUN apt-get -y install curl
+RUN apt-get -y install make python3
+RUN ln -fs /usr/bin/python3 /usr/local/bin/python
 
 RUN mkdir -p /mal
 WORKDIR /mal
diff --git a/impls/common-lisp/Dockerfile b/impls/common-lisp/Dockerfile
index 447f413bbb..7b43e47f02 100644
--- a/impls/common-lisp/Dockerfile
+++ b/impls/common-lisp/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/cs/Dockerfile b/impls/cs/Dockerfile
index f5f133484d..a95c31ce18 100644
--- a/impls/cs/Dockerfile
+++ b/impls/cs/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -22,4 +22,4 @@ WORKDIR /mal
 ##########################################################
 
 # Deps for Mono-based languages (C#, VB.Net)
-RUN apt-get -y install mono-runtime mono-mcs mono-vbnc mono-devel
+RUN apt-get -y install tzdata mono-runtime mono-mcs mono-vbnc mono-devel
diff --git a/impls/forth/Dockerfile b/impls/forth/Dockerfile
index c84caec2c4..4a0be33d86 100644
--- a/impls/forth/Dockerfile
+++ b/impls/forth/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/fsharp/Dockerfile b/impls/fsharp/Dockerfile
index 01cf8044c7..67ca2243b1 100644
--- a/impls/fsharp/Dockerfile
+++ b/impls/fsharp/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -22,6 +22,6 @@ WORKDIR /mal
 ##########################################################
 
 # Deps for Mono-based languages (C#, VB.Net)
-RUN apt-get -y install mono-runtime mono-mcs mono-vbnc mono-devel
+RUN apt-get -y install tzdata mono-runtime mono-mcs mono-vbnc mono-devel
 
 RUN apt-get -y install fsharp
diff --git a/impls/groovy/Dockerfile b/impls/groovy/Dockerfile
index 196698ab78..938f5aa0c0 100644
--- a/impls/groovy/Dockerfile
+++ b/impls/groovy/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -22,7 +22,7 @@ WORKDIR /mal
 ##########################################################
 
 # Java and Groovy
-RUN apt-get -y install openjdk-7-jdk
+RUN apt-get -y install openjdk-8-jdk
 #RUN apt-get -y install maven2
 #ENV MAVEN_OPTS -Duser.home=/mal
 RUN apt-get -y install ant
diff --git a/impls/io/Dockerfile b/impls/io/Dockerfile
index e93a326434..beeb46b03c 100644
--- a/impls/io/Dockerfile
+++ b/impls/io/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/kotlin/Dockerfile b/impls/kotlin/Dockerfile
index dfb83bb887..86857b2ce1 100644
--- a/impls/kotlin/Dockerfile
+++ b/impls/kotlin/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -22,7 +22,7 @@ WORKDIR /mal
 ##########################################################
 
 # Java and Zip
-RUN apt-get -y install openjdk-7-jdk
+RUN apt-get -y install openjdk-8-jdk
 RUN apt-get -y install unzip
 
 RUN curl -O -J -L https://github.com/JetBrains/kotlin/releases/download/v1.0.6/kotlin-compiler-1.0.6.zip
diff --git a/impls/make/Dockerfile b/impls/make/Dockerfile
index 5f61062ee3..0890fa83de 100644
--- a/impls/make/Dockerfile
+++ b/impls/make/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:24.04
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -9,7 +9,8 @@ MAINTAINER Joel Martin <github@martintribe.org>
 RUN apt-get -y update
 
 # Required for running tests
-RUN apt-get -y install make python
+RUN apt-get -y install make python3
+RUN ln -fs /usr/bin/python3 /usr/local/bin/python
 
 # Some typical implementation and test requirements
 RUN apt-get -y install curl libreadline-dev libedit-dev
diff --git a/impls/miniMAL/Dockerfile b/impls/miniMAL/Dockerfile
index fa54933ccb..87a5dcfb3f 100644
--- a/impls/miniMAL/Dockerfile
+++ b/impls/miniMAL/Dockerfile
@@ -1,5 +1,7 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 MAINTAINER Joel Martin <github@martintribe.org>
+LABEL org.opencontainers.image.source=https://github.com/kanaka/mal
+LABEL org.opencontainers.image.description="mal test container: miniMAL"
 
 ##########################################################
 # General requirements for testing or common across many
@@ -9,7 +11,8 @@ MAINTAINER Joel Martin <github@martintribe.org>
 RUN apt-get -y update
 
 # Required for running tests
-RUN apt-get -y install make python
+RUN apt-get -y install make python3
+RUN ln -sf /usr/bin/python3 /usr/bin/python
 
 # Some typical implementation and test requirements
 RUN apt-get -y install curl libreadline-dev libedit-dev
@@ -24,14 +27,9 @@ WORKDIR /mal
 # For building node modules
 RUN apt-get -y install g++
 
-# Add nodesource apt repo config for 10.x stable
-RUN apt-get -y install gnupg
-RUN curl -sL https://deb.nodesource.com/setup_10.x | bash -
-
-# Install nodejs
-RUN apt-get -y install nodejs
+RUN apt-get -y install nodejs npm
 
 ENV NPM_CONFIG_CACHE /mal/.npm
 
 # install miniMAL
-RUN npm install -g minimal-lisp
+RUN npm install -g minimal-lisp@1.2.2
diff --git a/impls/miniMAL/core.json b/impls/miniMAL/core.json
index d80efad732..3ad9bd0926 100644
--- a/impls/miniMAL/core.json
+++ b/impls/miniMAL/core.json
@@ -10,6 +10,12 @@
   ["and", ["string?", "s"],
           ["not", ["=", ["`", "\u029e"], ["get", "s", 0]]]]]],
 
+["def", "_function?", ["fn", ["a"],
+  ["isa", "a", "Function"]]],
+
+["def", "_number?", ["fn", ["a"],
+  ["=", ["`", "[object Number]"], ["classOf", "a"]]]],
+
 ["def", "div", ["fn", ["a", "b"], ["parseInt", ["/", "a", "b"]]]],
 
 ["def", "time-ms", ["fn", [],
@@ -121,9 +127,9 @@
    ["`", "symbol?"], "symbol?",
    ["`", "keyword"], "keyword",
    ["`", "keyword?"], "keyword?",
-   ["`", "number?"], "number?",
+   ["`", "number?"], "_number?",
    ["`", "fn?"], ["fn", ["a"],
-                   ["or", ["function?", "a"],
+                   ["or", ["_function?", "a"],
                           ["and", ["malfunc?", "a"],
                                   ["not", ["get", "a", ["`", "macro?"]]]]]],
    ["`", "macro?"], ["fn", ["a"],
diff --git a/impls/miniMAL/miniMAL-core.json b/impls/miniMAL/miniMAL-core.json
index cc3379f0e7..d430c1fdae 100644
--- a/impls/miniMAL/miniMAL-core.json
+++ b/impls/miniMAL/miniMAL-core.json
@@ -1,124 +1,5 @@
 ["do",
 
-["def", "new", ["fn", ["a", "&", "b"],
-  [".", "Reflect", ["`", "construct"], "a", "b"]]],
-["def", "del", ["fn", ["a", "b"],
-  [".", "Reflect", ["`", "deleteProperty"], "a", "b"]]],
-["def", "map", ["fn", ["a", "b"],
-  [".", "b", ["`", "map"], ["fn", ["x"], ["a", "x"]]]]],
-["def", "list", ["fn", ["&", "a"], "a"]],
-["def", ">=", ["fn", ["a", "b"],
-  ["if", ["<", "a", "b"], false, true]]],
-["def", ">", ["fn", ["a", "b"],
-  ["if", [">=", "a", "b"],
-    ["if", ["=", "a", "b"], false, true],
-    false]]],
-["def", "<=", ["fn", ["a", "b"],
-  ["if", [">", "a", "b"], false, true]]],
-
-["def", "classOf", ["fn", ["a"],
-  [".", [".-", [".-", "Object", ["`", "prototype"]], ["`", "toString"]],
-        ["`", "call"], "a"]]],
-
-["def", "not", ["fn", ["a"], ["if", "a", false, true]]],
-
-["def", "null?", ["fn", ["a"], ["=", null, "a"]]],
-["def", "true?", ["fn", ["a"], ["=", true, "a"]]],
-["def", "false?", ["fn", ["a"], ["=", false, "a"]]],
-["def", "string?", ["fn", ["a"],
-  ["if", ["=", "a", null],
-    false,
-    ["=", ["`", "String"],
-          [".-", [".-", "a", ["`", "constructor"]],
-                 ["`", "name"]]]]]],
-["def", "number?", ["fn", ["a"],
-  ["=", ["`", "[object Number]"], ["classOf", "a"]]]],
-["def", "function?", ["fn", ["a"],
-  ["isa", "a", "Function"]]],
-
-["def", "pr-list*", ["fn", ["a", "b", "c"],
-  [".", ["map", ["fn", ["x"],
-                  ["if", "c",
-                    [".", "JSON", ["`", "stringify"], "x"],
-                    ["if", ["string?", "x"],
-                      "x",
-                      [".", "JSON", ["`", "stringify"], "x"]]]],
-              "a"],
-      ["`", "join"], "b"]]],
-["def", "pr-str", ["fn", ["&", "a"],
-  ["pr-list*", "a", ["`", " "], true]]],
-["def", "str", ["fn", ["&", "a"],
-  ["pr-list*", "a", ["`", ""], false]]],
-["def", "prn", ["fn", ["&", "a"],
-  ["do", [".", "console", ["`", "log"],
-           ["pr-list*", "a", ["`", " "], true]], null]]],
-["def", "println", ["fn", ["&", "a"],
-  ["do", [".", "console", ["`", "log"],
-           ["pr-list*", "a", ["`", " "], false]], null]]],
-
-["def", "list?", ["fn", ["a"],
-  [".", "Array", ["`", "isArray"], "a"]]],
-["def", "contains?", ["fn", ["a", "b"],
-  [".", "a", ["`", "hasOwnProperty"], "b"]]],
-["def", "get", ["fn", ["a", "b"],
-    ["if", ["contains?", "a", "b"], [".-", "a", "b"], null]]],
-["def", "set", ["fn", ["a", "b", "c"],
-  ["do", [".-", "a", "b", "c"], "a"]]],
-["def", "keys", ["fn", ["a"],
-  [".", "Object", ["`", "keys"], "a"]]],
-["def", "vals", ["fn", ["a"],
-  ["map",["fn", ["k"], ["get", "a", "k"]], ["keys", "a"]]]],
-
-["def", "cons", ["fn", ["a", "b"],
-  [".", ["`", []],
-        ["`", "concat"], ["list", "a"], "b"]]],
-["def", "concat", ["fn", ["&", "a"],
-  [".", [".-", ["list"], ["`", "concat"]],
-        ["`", "apply"], ["list"], "a"]]],
-["def", "nth", "get"],
-["def", "first", ["fn", ["a"],
-  ["if", [">", [".-", "a", ["`", "length"]], 0],
-    ["nth", "a", 0],
-    null]]],
-["def", "last", ["fn", ["a"],
-  ["nth", "a", ["-", [".-", "a", ["`", "length"]], 1]]]],
-["def", "count", ["fn", ["a"],
-  [".-", "a", ["`", "length"]]]],
-["def", "empty?", ["fn", ["a"],
-  ["if", ["list?", "a"],
-    ["if", ["=", 0, [".-", "a", ["`", "length"]]], true, false],
-    ["=", "a", null]]]],
-["def", "slice", ["fn", ["a", "b", "&", "end"],
-  [".", "a", ["`", "slice"], "b",
-    ["if", [">", ["count", "end"], 0],
-      ["get", "end", 0],
-      [".-", "a", ["`", "length"]]]]]],
-["def", "rest", ["fn", ["a"], ["slice", "a", 1]]],
-
-["def", "apply", ["fn", ["f", "&", "b"],
-  [".", "f", ["`", "apply"], "f",
-    ["concat", ["slice", "b", 0, -1], ["last", "b"]]]]],
-
-["def", "and", ["~", ["fn", ["&", "xs"],
-  ["if", ["empty?", "xs"],
-    true,
-    ["if", ["=", 1, ["count", "xs"]],
-      ["first", "xs"],
-      ["list", ["`", "let"], ["list", ["`", "and_FIXME"], ["first", "xs"]],
-        ["list", ["`", "if"], ["`", "and_FIXME"],
-          ["concat", ["`", ["and"]], ["rest", "xs"]],
-          ["`", "and_FIXME"]]]]]]]],
-
-["def", "or", ["~", ["fn", ["&", "xs"],
-  ["if", ["empty?", "xs"],
-    null,
-    ["if", ["=", 1, ["count", "xs"]],
-      ["first", "xs"],
-      ["list", ["`", "let"], ["list", ["`", "or_FIXME"], ["first", "xs"]],
-        ["list", ["`", "if"], ["`", "or_FIXME"],
-          ["`", "or_FIXME"],
-          ["concat", ["`", ["or"]], ["rest", "xs"]]]]]]]]],
-
 ["def", "repl", ["fn",["prompt", "rep"],
   ["let", ["readline", ["require", ["`", "readline"]],
            "opts", ["new", "Object"],
diff --git a/impls/miniMAL/package.json b/impls/miniMAL/package.json
index bd9e2cf659..99f902b20e 100644
--- a/impls/miniMAL/package.json
+++ b/impls/miniMAL/package.json
@@ -4,6 +4,6 @@
     "description": "Make a Lisp (mal) language implemented in miniMAL",
     "dependencies": {
         "minimal-lisp": "1.0.2",
-        "ffi-napi": "2.4.x"
+        "ffi-napi": "4.0.3"
     }
 }
diff --git a/impls/miniMAL/step6_file.json b/impls/miniMAL/step6_file.json
index 214a83cfc3..1e954c740c 100644
--- a/impls/miniMAL/step6_file.json
+++ b/impls/miniMAL/step6_file.json
@@ -100,14 +100,14 @@
 ["env-set", "repl-env", ["symbol", ["`", "eval"]],
                         ["fn", ["ast"], ["EVAL", "ast", "repl-env"]]],
 ["env-set", "repl-env", ["symbol", ["`", "*ARGV*"]],
-                        ["slice", "ARGS", 1]],
+                        ["slice", "argv", 1]],
 
 ["`", "core.mal: defined using mal itself"],
 ["rep", ["`", "(def! not (fn* (a) (if a false true)))"]],
 ["rep", ["`", "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \"\nnil)\")))))"]],
 
-["if", ["not", ["empty?", "ARGS"]],
-  ["rep", ["str", ["`", "(load-file \""], ["get", "ARGS", 0], ["`", "\")"]]],
+["if", ["not", ["empty?", "argv"]],
+  ["rep", ["str", ["`", "(load-file \""], ["get", "argv", 0], ["`", "\")"]]],
   ["repl", ["`", "user> "], "rep"]],
 
 null
diff --git a/impls/miniMAL/step7_quote.json b/impls/miniMAL/step7_quote.json
index 44baaacc37..e11f1d7fce 100644
--- a/impls/miniMAL/step7_quote.json
+++ b/impls/miniMAL/step7_quote.json
@@ -131,14 +131,14 @@
 ["env-set", "repl-env", ["symbol", ["`", "eval"]],
                         ["fn", ["ast"], ["EVAL", "ast", "repl-env"]]],
 ["env-set", "repl-env", ["symbol", ["`", "*ARGV*"]],
-                        ["slice", "ARGS", 1]],
+                        ["slice", "argv", 1]],
 
 ["`", "core.mal: defined using mal itself"],
 ["rep", ["`", "(def! not (fn* (a) (if a false true)))"]],
 ["rep", ["`", "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \"\nnil)\")))))"]],
 
-["if", ["not", ["empty?", "ARGS"]],
-  ["rep", ["str", ["`", "(load-file \""], ["get", "ARGS", 0], ["`", "\")"]]],
+["if", ["not", ["empty?", "argv"]],
+  ["rep", ["str", ["`", "(load-file \""], ["get", "argv", 0], ["`", "\")"]]],
   ["repl", ["`", "user> "], "rep"]],
 
 null
diff --git a/impls/miniMAL/step8_macros.json b/impls/miniMAL/step8_macros.json
index cafceb3f5d..d4b54576c1 100644
--- a/impls/miniMAL/step8_macros.json
+++ b/impls/miniMAL/step8_macros.json
@@ -137,15 +137,15 @@
 ["env-set", "repl-env", ["symbol", ["`", "eval"]],
                         ["fn", ["ast"], ["EVAL", "ast", "repl-env"]]],
 ["env-set", "repl-env", ["symbol", ["`", "*ARGV*"]],
-                        ["slice", "ARGS", 1]],
+                        ["slice", "argv", 1]],
 
 ["`", "core.mal: defined using mal itself"],
 ["rep", ["`", "(def! not (fn* (a) (if a false true)))"]],
 ["rep", ["`", "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \"\nnil)\")))))"]],
 ["rep", ["`", "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))"]],
 
-["if", ["not", ["empty?", "ARGS"]],
-  ["rep", ["str", ["`", "(load-file \""], ["get", "ARGS", 0], ["`", "\")"]]],
+["if", ["not", ["empty?", "argv"]],
+  ["rep", ["str", ["`", "(load-file \""], ["get", "argv", 0], ["`", "\")"]]],
   ["repl", ["`", "user> "], "rep"]],
 
 null
diff --git a/impls/miniMAL/step9_try.json b/impls/miniMAL/step9_try.json
index f9140b71f8..05090ab9f8 100644
--- a/impls/miniMAL/step9_try.json
+++ b/impls/miniMAL/step9_try.json
@@ -150,15 +150,15 @@
 ["env-set", "repl-env", ["symbol", ["`", "eval"]],
                         ["fn", ["ast"], ["EVAL", "ast", "repl-env"]]],
 ["env-set", "repl-env", ["symbol", ["`", "*ARGV*"]],
-                        ["slice", "ARGS", 1]],
+                        ["slice", "argv", 1]],
 
 ["`", "core.mal: defined using mal itself"],
 ["rep", ["`", "(def! not (fn* (a) (if a false true)))"]],
 ["rep", ["`", "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \"\nnil)\")))))"]],
 ["rep", ["`", "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))"]],
 
-["if", ["not", ["empty?", "ARGS"]],
-  ["rep", ["str", ["`", "(load-file \""], ["get", "ARGS", 0], ["`", "\")"]]],
+["if", ["not", ["empty?", "argv"]],
+  ["rep", ["str", ["`", "(load-file \""], ["get", "argv", 0], ["`", "\")"]]],
   ["repl", ["`", "user> "], "rep"]],
 
 null
diff --git a/impls/miniMAL/stepA_mal.json b/impls/miniMAL/stepA_mal.json
index f7eec832bc..0f068a4e2a 100644
--- a/impls/miniMAL/stepA_mal.json
+++ b/impls/miniMAL/stepA_mal.json
@@ -150,7 +150,7 @@
 ["env-set", "repl-env", ["symbol", ["`", "eval"]],
                         ["fn", ["ast"], ["EVAL", "ast", "repl-env"]]],
 ["env-set", "repl-env", ["symbol", ["`", "*ARGV*"]],
-                        ["slice", "ARGS", 1]],
+                        ["slice", "argv", 1]],
 
 ["`", "core.mal: defined using mal itself"],
 ["rep", ["`", "(def! *host-language* \"miniMAL\")"]],
@@ -158,8 +158,8 @@
 ["rep", ["`", "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \"\nnil)\")))))"]],
 ["rep", ["`", "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))"]],
 
-["if", ["not", ["empty?", "ARGS"]],
-  ["rep", ["str", ["`", "(load-file \""], ["get", "ARGS", 0], ["`", "\")"]]],
+["if", ["not", ["empty?", "argv"]],
+  ["rep", ["str", ["`", "(load-file \""], ["get", "argv", 0], ["`", "\")"]]],
   ["do",
     ["rep", ["`", "(println (str \"Mal [\" *host-language* \"]\"))"]],
     ["repl", ["`", "user> "], "rep"]]],
diff --git a/impls/objpascal/Dockerfile b/impls/objpascal/Dockerfile
index 31bb193b10..743ec8bbea 100644
--- a/impls/objpascal/Dockerfile
+++ b/impls/objpascal/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:24.04
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -9,7 +9,8 @@ MAINTAINER Joel Martin <github@martintribe.org>
 RUN apt-get -y update
 
 # Required for running tests
-RUN apt-get -y install make python
+RUN apt-get -y install make python3
+RUN ln -fs /usr/bin/python3 /usr/local/bin/python
 
 # Some typical implementation and test requirements
 RUN apt-get -y install curl libreadline-dev libedit-dev
diff --git a/impls/ocaml/Dockerfile b/impls/ocaml/Dockerfile
index 399553dbc3..4f7392ab3b 100644
--- a/impls/ocaml/Dockerfile
+++ b/impls/ocaml/Dockerfile
@@ -1,4 +1,4 @@
-[FROM ubuntu:vivid
+FROM ubuntu:24.04
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -9,7 +9,8 @@ MAINTAINER Joel Martin <github@martintribe.org>
 RUN apt-get -y update
 
 # Required for running tests
-RUN apt-get -y install make python
+RUN apt-get -y install make python3
+RUN ln -fs /usr/bin/python3 /usr/local/bin/python
 
 # Some typical implementation and test requirements
 RUN apt-get -y install curl libreadline-dev libedit-dev
diff --git a/impls/perl/Dockerfile b/impls/perl/Dockerfile
index b36833e072..24fd51c4c1 100644
--- a/impls/perl/Dockerfile
+++ b/impls/perl/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/perl6/Dockerfile b/impls/perl6/Dockerfile
index ea081e882a..d77ab0de62 100644
--- a/impls/perl6/Dockerfile
+++ b/impls/perl6/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:24.04
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -9,10 +9,8 @@ MAINTAINER Joel Martin <github@martintribe.org>
 RUN apt-get -y update
 
 # Required for running tests
-RUN apt-get -y install make python
-
-# Some typical implementation and test requirements
-RUN apt-get -y install curl libreadline-dev libedit-dev
+RUN apt-get -y install make python3
+RUN ln -fs /usr/bin/python3 /usr/local/bin/python
 
 RUN mkdir -p /mal
 WORKDIR /mal
@@ -22,13 +20,4 @@ WORKDIR /mal
 ##########################################################
 
 # Perl6 build deps
-RUN apt-get -y install libfile-copy-recursive-perl build-essential git
-
-RUN curl -O http://rakudo.org/downloads/star/rakudo-star-2016.07.tar.gz && \
-    tar xzf rakudo-star-2016.07.tar.gz && \
-    cd rakudo-star-2016.07 && \
-    perl Configure.pl --prefix=/usr --gen-moar --gen-nqp --backends=moar && \
-    make && \
-    make install && \
-    cd .. && \
-    rm -rf rakudo-star-2016.07*
+RUN apt-get -y install rakudo
diff --git a/impls/php/Dockerfile b/impls/php/Dockerfile
index 87709d4d9a..140e560177 100644
--- a/impls/php/Dockerfile
+++ b/impls/php/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -21,4 +21,4 @@ WORKDIR /mal
 # Specific implementation requirements
 ##########################################################
 
-RUN apt-get -y install php5-cli
+RUN apt-get -y install php7.0-cli
diff --git a/impls/powershell/reader.psm1 b/impls/powershell/reader.psm1
index bd7f95c34b..06ac18bdd4 100644
--- a/impls/powershell/reader.psm1
+++ b/impls/powershell/reader.psm1
@@ -40,7 +40,7 @@ function read_atom([Reader] $rdr) {
         return $s
     } elseif ($token -match "^`".*") {
         throw "expected '`"', got EOF"
-    } elseif ($token -match ":.*") {
+    } elseif ($token -match "^:.*") {
         return "$([char]0x29e)$($token.substring(1))"
     } elseif ($token -eq "true") {
         return $true
diff --git a/impls/prolog/reader.pl b/impls/prolog/reader.pl
index 515f67c69d..63846c5a22 100644
--- a/impls/prolog/reader.pl
+++ b/impls/prolog/reader.pl
@@ -63,3 +63,4 @@
 symcode(0'?).
 symcode(0'_).
 symcode(0'|).
+symcode(0':).
diff --git a/impls/ps/Dockerfile b/impls/ps/Dockerfile
index d91f68e1ea..a57b968803 100644
--- a/impls/ps/Dockerfile
+++ b/impls/ps/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/python/Dockerfile b/impls/python/Dockerfile
index 3e64cc116c..623eb4c9cb 100644
--- a/impls/python/Dockerfile
+++ b/impls/python/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/r/Dockerfile b/impls/r/Dockerfile
index 42611aeca2..0d19cecbe8 100644
--- a/impls/r/Dockerfile
+++ b/impls/r/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/racket/Dockerfile b/impls/racket/Dockerfile
index 1b05ee258b..cb97d4656b 100644
--- a/impls/racket/Dockerfile
+++ b/impls/racket/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/ruby/Dockerfile b/impls/ruby/Dockerfile
index 3bda3bf706..a50818b687 100644
--- a/impls/ruby/Dockerfile
+++ b/impls/ruby/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/ruby/step6_file.rb b/impls/ruby/step6_file.rb
index a4828e8640..c639926836 100644
--- a/impls/ruby/step6_file.rb
+++ b/impls/ruby/step6_file.rb
@@ -108,6 +108,6 @@ def PRINT(exp)
         puts REP[line]
     rescue Exception => e
         puts "Error: #{e}" 
-        puts "\t#{e.backtrace.join("\n\t")}"
+        puts "\t#{e.backtrace[0..100].join("\n\t")}"
     end
 end
diff --git a/impls/ruby/step7_quote.rb b/impls/ruby/step7_quote.rb
index 19d0fe7574..a9a4e33ca5 100644
--- a/impls/ruby/step7_quote.rb
+++ b/impls/ruby/step7_quote.rb
@@ -143,6 +143,6 @@ def PRINT(exp)
         puts REP[line]
     rescue Exception => e
         puts "Error: #{e}" 
-        puts "\t#{e.backtrace.join("\n\t")}"
+        puts "\t#{e.backtrace[0..100].join("\n\t")}"
     end
 end
diff --git a/impls/ruby/step8_macros.rb b/impls/ruby/step8_macros.rb
index 3b6873ccc8..01150de4c2 100644
--- a/impls/ruby/step8_macros.rb
+++ b/impls/ruby/step8_macros.rb
@@ -152,6 +152,6 @@ def PRINT(exp)
         puts REP[line]
     rescue Exception => e
         puts "Error: #{e}" 
-        puts "\t#{e.backtrace.join("\n\t")}"
+        puts "\t#{e.backtrace[0..100].join("\n\t")}"
     end
 end
diff --git a/impls/ruby/step9_try.rb b/impls/ruby/step9_try.rb
index 2ddb775234..84357f46cf 100644
--- a/impls/ruby/step9_try.rb
+++ b/impls/ruby/step9_try.rb
@@ -171,6 +171,6 @@ def PRINT(exp)
         else
             puts "Error: #{e}" 
         end
-        puts "\t#{e.backtrace.join("\n\t")}"
+        puts "\t#{e.backtrace[0..100].join("\n\t")}"
     end
 end
diff --git a/impls/ruby/stepA_mal.rb b/impls/ruby/stepA_mal.rb
index 34cc005eee..787fb578f0 100644
--- a/impls/ruby/stepA_mal.rb
+++ b/impls/ruby/stepA_mal.rb
@@ -179,6 +179,6 @@ def PRINT(exp)
         else
             puts "Error: #{e}" 
         end
-        puts "\t#{e.backtrace.join("\n\t")}"
+        puts "\t#{e.backtrace[0..100].join("\n\t")}"
     end
 end
diff --git a/impls/swift5/Sources/core/Reader.swift b/impls/swift5/Sources/core/Reader.swift
index 32f70c4093..287cfe83d0 100644
--- a/impls/swift5/Sources/core/Reader.swift
+++ b/impls/swift5/Sources/core/Reader.swift
@@ -84,7 +84,7 @@ private extension Parsers {
     // MARK: - Symbol
 
     static let symbolHead = char(excluding: "0123456789^`'\"#~@:%()[]{} \n\r\t,")
-    static let symbolRest = oneOf(symbolHead, char(from: "0123456789."))
+    static let symbolRest = oneOf(symbolHead, char(from: "0123456789.:"))
     static let name = (symbolHead <*> symbolRest.zeroOrMore).map { String($0) + String($1) }
     static let symbol = name.map(Expr.symbol)
 
diff --git a/impls/tcl/Dockerfile b/impls/tcl/Dockerfile
index 2ad3f330c3..337d63c7c5 100644
--- a/impls/tcl/Dockerfile
+++ b/impls/tcl/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
diff --git a/impls/tests/step1_read_print.mal b/impls/tests/step1_read_print.mal
index 403af6b49f..4afd4bfeba 100644
--- a/impls/tests/step1_read_print.mal
+++ b/impls/tests/step1_read_print.mal
@@ -233,6 +233,10 @@ false
 @a
 ;=>(deref a)
 
+;; Colon character inside a symbol
+a:
+;=>a:
+
 ;>>> soft=True
 ;>>> optional=True
 ;;
diff --git a/impls/vb/Dockerfile b/impls/vb/Dockerfile
index f5f133484d..a95c31ce18 100644
--- a/impls/vb/Dockerfile
+++ b/impls/vb/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:vivid
+FROM ubuntu:xenial
 MAINTAINER Joel Martin <github@martintribe.org>
 
 ##########################################################
@@ -22,4 +22,4 @@ WORKDIR /mal
 ##########################################################
 
 # Deps for Mono-based languages (C#, VB.Net)
-RUN apt-get -y install mono-runtime mono-mcs mono-vbnc mono-devel
+RUN apt-get -y install tzdata mono-runtime mono-mcs mono-vbnc mono-devel
diff --git a/process/guide.md b/process/guide.md
index 415ce23605..7fa072339f 100644
--- a/process/guide.md
+++ b/process/guide.md
@@ -1216,7 +1216,7 @@ Mal borrows most of its syntax and feature-set).
     then `ast`.
   - Else return `ast` unchanged.
     Such forms are not affected by evaluation, so you may quote them
-    as in the previous case if implementation is easyer.
+    as in the previous case if implementation is easier.
 
 * Add the `quasiquote` special form.
 
@@ -1715,9 +1715,7 @@ implementation.
 
 ### Next Steps
 
-* Join the #mal IRC channel. It's fairly quiet but there are bursts of
-  interesting conversation related to mal, Lisps, esoteric programming
-  languages, etc.
+* Join our [Discord](https://discord.gg/CKgnNbJBpF) channel.
 * If you have created an implementation for a new target language (or
   a unique and interesting variant of an existing implementation),
   consider sending a pull request to add it into the main mal
diff --git a/voom-like-version.sh b/voom-like-version.sh
new file mode 100755
index 0000000000..9e85e92770
--- /dev/null
+++ b/voom-like-version.sh
@@ -0,0 +1,3 @@
+#!/usr/bin/env sh
+
+echo $(TZ=UTC git log -1 --pretty=%ad-g%h --date=format-local:"%Y%m%d_%H%M%S" -- "$@")$(test -z "$(git status --short -- "$@")" || echo _DIRTY)