Check out the Sharetronix project page on sourceforge.net. You can find the source code on the subversion repository. This SVN will help you easily develop your own features and stuff for Sharetronix and share them with the Sharetronix community.
Check out the Translation center - it's an online tool that allows you to easily translate Sharetronix to your desired language. You can choose any one of the existing languages to use as a language base. After you complete the translation, you can download the generated files for your use and also share your work as one a contributing translator.
Our community network has over 2000 members. Here are some interesting official and unofficial groups: