If you are using a released version of LLVM, see the download page to find your documentation.
The LLVM compiler infrastructure supports a wide range of projects, from industrial strength compilers to specialized JIT applications to small research projects.
Similarly, documentation is broken down into several high-level groupings targeted at different audiences:
Several introductory papers and presentations.
For those new to the LLVM system.
NOTE: If you are a user who is only interested in using LLVM-based compilers, you should look into Clang or DragonEgg instead. The documentation here is intended for users who have a need to work with the intermediate LLVM representation.
For developers of applications which use LLVM as a library.
For API clients and LLVM developers.
Information about LLVM’s development process.
LLVM has a thriving community of friendly and helpful developers. The two primary communication mechanisms in the LLVM community are mailing lists and IRC.
If you can’t find what you need in these docs, try consulting the mailing lists.
Users and developers of the LLVM project (including subprojects such as Clang) can be found in #llvm on irc.oftc.net.
This channel has several bots.