Zitrone Mapping is an independent mapping group that is creating maps for Team Fortress Classic (Half-Life/Goldsource) and Trackmania (TMUF engine). We are particulary making remakes of famous Team Fortress Classic maps.
Have you ever wondered about the filename? For [TFC] Freefall, it's "zt07_freefall" (or zt07_ff in the new formatting). The first part ("zt") means Zitrone Mapping. Zitrone is German and means lemon. The two numbers stand for the year of release, 2007. Then an underscore, and the abbreviation of the project. The abbreviations were introduced just after the release of ZT07 Freefall.
If you want to contact Zitrone Mapping, you can write an email to (English + Deutsch).