All my publicly available codes are now available on GitHub.
I list below a few external tools that I found extremely useful for everyday's work.

Eclipse library

The ESO eclipse library also contains very useful tools, such as the dfits, dtfits and fitsort utilities. The library is not maintained any longer, but it should compile on most recent systems:
ESO eclipse library page
Local copies of dfits/dtfits/fitsort for Linux and Mac OS X