Wikipedia
Askbot
Askbot is an open source question and answer oriented Internet forum started on July 2009, similar to Stack Overflow or Yahoo! Answers. Based on CNPROG and some code written for OSQA, it is primarily developed and maintained by Evgeny Fadeev.
Large open source software projects like Fedora and LibreOffice use it as their main Q&A website. The Document Foundation put some funds in AskBot development.