Hello!
Right now, Open Arena uses Fileplanet to distribute files, and frankly, that sucks. You need to register, just to download the files :-(
Also, it is only possible to download 'complete' releases, not the current developer version. If Open Arena used CVS, it would be possible to get more involved into what's happening currently -> development would be faster.
Open Arena could apply for free hosting, CVS, etc. on (for example) these sites:
http://savannah.nongnu.org/https://gna.org/http://sourceforge.net/Greetings,
Jeroen