About the Atheme IRC Platform
Atheme is developed by the Atheme Development Group, an open-source development collective. Anyone can participate in the Atheme development process through GitHub. Contributors with an acceptable skillset and broad vision for the project are given commit access.
Atheme is extremely scalable, being used on many of IRC's largest networks, such as freenode.
Atheme was originally built on top of Shrike, a legacy minimalistic services package. The developers of Atheme decided that Shrike was a good basis to build a more full-featured services package from, based on their previous experience of contributing to Shrike. Little of the original code from Shrike remains, however many design concepts do.