The LLVM Developers' Meeting is intended for users and developers of LLVM. The 2014 event is taking place on the 28th and 29th of October in San Jose, California. Attendance will be limited to the first 300 participants.
The LLVM Foundation has issued a Call For Papers for those interested in presenting their LLVM-related work.
You can learn more about the 2014 LLVM Developers' Meeting via the mailing list announcement and LLVM.org event site.