Garry's Mod FastDL Generator is a small script created to aid Garry's Mod server management.
Simply put, this will scan a given directory and compress (Using the Source-compatible BZ2) certain files - depending on their size post-compression.
The script will output these size-optimized files into the given directory and will even generate a file containing all the necessary Lua code - resource.AddFile(). (Just put the file inside of 'lua/autorun/' on your server!).
NOTE: This script has yet to be compiled; so will require a valid installation of Python 3.x and PyQt4!