Project Community
Infinispan has an active community. If you are interested in participating, this is probably your starting point. Use the links on the right to access various facets of the project, although the Quick Start for Developers page is a must-read if you are interested in contributing to the project.
Community content - including documentation, wiki pages, tutorials, examples and discussions are all available on Infinispan's community site.
IRC
In addition to the mailing list, Infinispan developers are often found on IRC, on channel #infinispan the Freenode network. Drop in and say hello.
Becoming a committer
To become a committer on Infinispan, you would typically need to have interacted with the community in some shape or form, and this usually includes using the forums, mailing lists and even IRC to discuss issues and suggest features. In most cases, this would also involve reporting bugs, writing test cases to prove bugs, and providing patches as well as writing documentation, wiki articles, etc.
If you feel your involvement with the community - based on the paragraph above - is sufficient to warrant commit access to the code base, please email the infinispan-dev mailing list to discuss this.