LensFun

For my favorite raw managing and editing software darktable, LensFun is a very important library. While the lib does its work mainly unnoticed tightly integrated in darktable, I basically use it in every photo I develop to correct the lens errors.
The program works flawless and developers actually provide an easy to use service to add missing data to the database providing sample photos if you cannot conduct the process yourself.
I'd like to thank all the devs for their work on this often not seen but very important image manipulation software.