There is no main project on github that gathers people, even though we can see a fair amount of MooseX:: projects. Most of the developers will work on different modules, that may not have the same purpose. Lately we have seen a fair amount of work on various Plack stuff, mainly middleware, but also HTTP servers (twiggy, starman, …) and web framework (dancer).
@franckcuny explored github for more languages and geographic informations, which results in beautiful graphs and posters. For Perl and Japanese graphs we can see how Plack and related projects connect people together. Awesome work!