Ungodly input configuration formats to deal with

For specific apps (with abominantions noted)

GULP: plain text, lots of abbreviations, most options take multiple arguments https://nanochemistry.curtin.edu.au/local/docs/gulp/example4.gin
CP2K: strange block format, ALL_CAPS http://wiki.wpi.edu/images/images/4/47/Sample-input-cp2k.pdf
VASP: Free order, possible to have comments without comment indicator (which is "!"). I still have no idea how that is achieved, I think you just have to avoid starting a line with any (possibly undocumented) valid tags? http://cms.mpi.univie.ac.at/vasp/guide/node91.html
AMBER: What do any of these random collections of letters mean, why should they be set to 3? http://ambermd.org/tutorials/basic/tutorial0/#Prepare_Amber_sander_input_files, also: https://twitter.com/jchodera/status/1021341652877656064

Note: External = not a part of VECMA