[*]

openMSX

the MSX emulator that aims for perfection

Contact

IRC

#openmsx on Freenode
You'll find most of the developers here on a regular basis. Don't hesitate to visit, don't hesitate to ask anything openMSX related. Remarks, suggestions, ideas—also for Catapult and C-BIOS—are most welcome!
For your convenience, we can also offer you web-based access to our IRC channel. Try it by following this link! It will open the chat room in a new window or a new tab. Change your nickname and join the chat!

Discussion Forums

openMSX forum
Discussions on openMSX, Catapult and C-BIOS.
SourceForge openMSX forums
SourceForge hosts a number of forums (two, at the moment) for openMSX.

Mailing Lists and Trackers

SourceForge openMSX mailing lists
SourceForge hosts a number of mailing lists for openMSX. None of these mailing lists is high-volume; expect just a couple of messages per week.
SourceForge openMSX Trackers
SourceForge also hosts trackers, that enable you to reports bugs, request new features etc. Note that you do need a SourceForge account to create new tracker items.