A better page will be put up for this but for the moment if you want to contact me you can do so at andy at gphpedit dot org.
If you want to get involved, feel free to contact me. I'm happy to accept patches for features or feature requests or reproducible bug reports!
gPHPEdit is in Sourceforge's CVS servers and there is a Developers mailing list hosted there too (although it's not very active as I am the only working on the project at the moment).