Starts adding high-level content and tutorials

docs/_data/navigation.yml

@@ -1,4 +1,6 @@
 main:
+  - title: "About"
+    url: "/about/"
   - title: "Plugins"
     url: "/plugins/"
   - title: "Community Members"

docs/_pages/about.md

@@ -0,0 +1,68 @@
+---
+title: "About the NWChemEx Project"
+layout: splash
+permalink: /about/
+---
+
+The short of it is NWChemEx is a quantum chemistry software package which
+strives to adhere to modern software engineering best practices. These practices
+champion a separation-of-concerns approach which results in a package with many
+well-defined pieces. Users benefit from the "app-store" like experience
+and developers benefit by being able to quickly inject code throughout the
+software for rapid prototyping, custom workflows, and performance tuning.
+
+## NWChemEx Focuses on Quantum Chemistry
+Chemistry is the study of matter, i.e., things made of atoms. The properties of 
+matter stem from how the constituent atoms interact. Given an arrangement of
+atoms, computational chemistry strives to accurately compute the interactions
+among the atoms and therefore the resulting properties. While the 
+equations for computing the atomic interactions for a set of atoms are known, 
+even with today's supercomputers these equations can only be exactly solved
+for systems containing a few atoms. Most systems of interest in chemistry 
+contain many molecules interacting with each other and usually each of the
+molecules contains somewhere on the order of 10 to 100 atoms. Exact solution
+for systems of chemical interest is unlikely to be possible any time soon.
+
+NWChemEx is targeted at providing high-performance implementations of quantum
+chemistry methods. Generally speaking, quantum chemistry methods remain 
+accurate by staying true to the physics of the system, but are also practical 
+because they only treat a subset of interactions. While more practical than
+the exact equations, most quantum chemistry methods still require a substantial
+amount of computational resources. NWChemEx actively strives to increase the
+applicability of quantum chemistry methods by developing new reduced cost
+algorithms and by taking full advantage of today's modern hardware.
+
+## NWChemEx Philosophy
+
+### User Friendly
+
+At launch NWChemEx has a limited selection of features; however, we strive to
+make using those features easy for users regardless of whether the user's use 
+case is a heroic exascale computation, a high-throughput campaign, or a
+teaching exercise for undergraduate physical chemistry. 
+
+For more details see [NWChemEx Community](/community/).
+
+### Ecosystem Friendly
+Many software developers within scientific computing are embracing modularity.
+This means there is an abundance of existing, open-source, performant software
+which can be leveraged in an algorithm instead of needing to "reinvent the 
+wheel." To capitalize on this, NWChemEx is built on a plugin system which makes 
+it easy for users to inject code ---be it an existing library, custom behavior,
+or an entire prototype routine --- into existing algorithms. Moreover this can
+be accomplished without needing to directly modify the existing code base.
+
+For more details see [NWChemEx Developers](/developer/).
+
+### Theory Friendly
+At present the majority of NWChemEx's development has been on infrastructure
+with the goal of making developing electronic structure theory easier. To that 
+end, NWChemEx embraces object-oriented programming (OOP). Using OOP it is much 
+easier to decouple the developer's intent from the optimization of that intent. 
+For example, using objects meant to represent wavefunctions and operators, the 
+developer can write a quantum chemistry method in a manner similar to what one 
+finds in a textbook. Under the hood, the wavefunction and operator classes can
+dispatch to routines which know how to efficiently form, compose, and operate
+on tensors. 
+
+For more details see [NWChemEx Authors](/author/).

docs/_pages/developer/home.md

@@ -4,4 +4,19 @@ layout: splash
 permalink: /developer/
 ---
 
-TODO: content
+The NWChemEx community views anyone who writes software which interfaces with
+NWChemEx as an NWChemEx developer. That said, the topics in this section will be 
+most useful if you are:
+
+- A developer/maintainer of an existing library, tool, or software package and
+  you want to make the library, tool, or software package interoperable with
+  the NWChemEx ecosystem.
+- A software developer looking to create a library, tool, or software package
+  and you want the library, tool, or software package to be readily usable by
+  the both the NWChemEx ecosystem and the broader community.
+
+# Table of Contents
+
+- [Overview of NWChemEx Development](/developer/overview/)
+- [Writing your first NWChemEx Plugin](/developer/your_first_plugin/)
+- [Writing your first NWChemEx Module](/developer/your_first_module/)

docs/_pages/developer/overview.md

@@ -0,0 +1,135 @@
+---
+title: "Overview of NWChemEx Development"
+layout: splash
+permalink: /developer/overview/
+---
+
+The NWChemEx ecosystem is predicated on the assumption that developers are 
+interested in creating and consuming modular software. Our purpose here is
+to provide enough conceptual background so that developers can understand
+what modules are and how modules interact with the rest of the NWChemEx 
+ecosystem. From there developers will be ready to begin learning how to write
+their first module.
+
+## What is a module?
+
+In software engineering, modules are defined as reusable, single-purpose units 
+of code that encapsulate their implementation details. The key aspects of this 
+definition are:
+
+- *Reusable.* A piece of software is reusable if it can be used from more than
+  one place.
+- *Single Purpose.* A module should do one task. To do multiple tasks use
+  multiple modules.
+- *Encapsulate.* Modules should be black-boxes, i.e., the caller of the module
+  should not care how the module does what it does.
+
+There are also several corollary properties that follow from this definition:
+
+- *Generalization.* A module must represent some sort of generalization. By 
+  contrast, if a code unit could only be used in a very specific situation it 
+  would not be reusable. 
+- *Discoverable.* Again follows from the reusable property. If we are to call a
+  module from multiple places it must be possible for each of those places
+  to find the module.
+- *Composable.* Each module performs one task. Usually those tasks are much
+  simpler than the user's goal. We thus must be able to use results from
+  multiple modules to achieve the goal.
+
+Ultimately the concept of a module provides a mechanism for managing the 
+complexity of a problem. More specifically, modules allow us to solve new
+problems by building on solved problems. For example, say we are trying to sort
+a list. Since modules for comparing elements of the list likely exist we can
+implement our algorithm in terms of such modules (if the modules did not exist 
+we could write them, or we could hard-code the the comparison into the module
+for the sorting algorithm). Similarly, if we were writing an algorithm 
+for finding the set of elements common to two lists, we will benefit from the 
+module for sorting a list.
+
+## What is modular software?
+
+At face value modular software is simply software which relies on modules. In
+practice almost all modern software is modular at some level; for example, it 
+probably uses functions, classes, and libraries to break the code up as
+opposed to dumping everything into one giant main function. The real difference
+between modular and non-modular software is what is called "cohesion." Cohesion 
+is the extent to which things bundled in a module belong together. Modules where
+everything "belongs together" are said to have "high-cohesion" whereas those
+which only somewhat belong together are said to have "low-cohesion". Software
+made of many high-cohesion modules is termed modular software whereas that
+relying on many low-cohesion modules is usually monolithic.
+
+Why does this matter? Decades of software engineering experience has shown that
+it is much harder to maintain, extend, and reuse low-cohesion modules. Moreover,
+software formed from low-cohesion modules tends to be more buggy, harder to
+use, and harder to extend. This is because modifying low-cohesion modules is
+a "game of whack-a-mole." Since low-cohesion modules bring together many
+loosely related pieces, changes to those pieces can easily break "distant"
+pieces of the software. By contrast, changes to high-cohesion modules tend to
+only have ramifications in the module.
+
+## Modularity within NWChemEx
+
+The fundamental premise of the NWChemEx ecosystem is that developers want 
+to develop high-performance, high-cohesion modules and that software
+should be designed in a way that capitalizes on such modules. To that end it is
+important to note that some modules, like those implementing 
+optimization algorithms, can be used in many different circumstances. Similarly,
+for many problems, there are often a number of different ways to get the same 
+solution (again optimization is a good example). Continuing with the optimizer
+example, one can imagine that users may have personal preferences for which 
+optimizer module to use where and/or want to immediately used a bleeding-edge
+module wherever optimization is needed. NWChemEx solves this by relying on
+dynamic loading of modules, i.e., the decision of which modules to use where
+is put off until the software is run.
+
+The NWChemEx ecosystem is comprised of plugins and 
+[SimDE](https://github.com/NWChemEx/SimDE). Plugins are libraries
+of modules which can be loaded dynamically and SimDE is the software development
+kit that contains the infrastructure for loading plugins as well as the 
+fundamental data structures and APIs needed to interface with plugins.  In 
+practice, this means "streamlined" NWChemEx calculations follow a pattern like:
+
+```python
+import simde
+import name_of_plugin
+
+# mm is an object capable of loading plugins
+mm = simde.pluginplay.ModuleManager()
+
+# Load the plugin using mm
+name_of_plugin.load_modules(mm)
+
+# Use mm to run your calculation
+```
+
+We say streamlined because most users won't run NWChemEx this way, rather they
+will do:
+
+```python
+import nwchemex as nwx
+
+mm = nwx.load_modules()
+
+# Usse mm to run your calculation
+```
+
+While this may be simpler from a code perspective this loads most of the
+plugins in the NWChemEx ecosystem and is significantly heavier in terms of
+dependencies.
+
+## Next Steps
+
+To start developing you will need to install SimDE and/or NWChemEx. Strictly
+speaking plugins can be created with SimDE alone; however, many developers find
+it easier to develop plugins if they can test them using other plugins in the
+ecosystem. See [here](/community/install/) for build instructions.
+
+If you want to learn how to develop a plugin see 
+[this](/developer/your_first_plugin/) tutorial.
+
+If you are contributing modules to an already existing plugin see
+[this](/developer/your_first_module/) tutorial.
+
+
+

docs/_pages/developer/your_first_module.md

@@ -0,0 +1,8 @@
+---
+title: "Writing your first NWChemEx Module"
+layout: splash
+permalink: /developer/your_first_module/
+toc: true
+---
+
+TODO: Write me!!!

docs/_pages/developer/your_first_plugin.md

@@ -0,0 +1,12 @@
+---
+title: "Writing your first NWChemEx Plugin"
+layout: splash
+permalink: /developer/your_first_plugin/
+toc: true
+---
+
+To make life easy the NWChemEx team has created a plugin template which can be 
+obtained by using the 
+[Cookiecutter](https://cookiecutter.readthedocs.io/en/stable/) python 
+package. Instructions for obtaining and configuring the template can be
+found [here](https://github.com/NWChemEx/PluginTemplate).

docs/_pages/home.md

@@ -37,8 +37,14 @@ gallery2:
 This website is under heavy construction at the moment.
 {: .notice--warning}
 
-Choose your experience. Don't know which experience you want? Visit our tutorial
-on [NWChemEx Community Roles](/tutorials/community_overview).
+New to NWChemEx? Check out our [about page](/about/) for a quick overview of the
+project and what we are trying to accomplish. Otherwise you can browse
+information by use case:
+
+- **Community members** run calculations.
+- **Developers** develop modular software compatible with NWChemEx.
+- **Authors** develop infrastructure and plugins for NWChemEx.
+
 
 {% include gallery id="gallery1" %}