LLVM C++ IDE for Windows
LLVM is supported in Eclipse CDT via plug-in (llvm4eclipsecdt). It is the only Windows supported IDE supporting LLVM as far as I know. I am the main author of the plug-in so you can ask any questions related to it.
The plug-in offers the basic functionality for Clang and llvm-gcc compilation and support Linux and Windows (w/ Cygwin & MiNGW). LLVM tools such as assembler, archiver, linker, and static compiler (llc) are configured and can be customized via UI. The plug-in offers all the benefits that IDE can offer such as easy configuration and building with one action.
The only drawback is that it is not ready yet as it lacks of some of the advanced features that LLVM can offer such as Clang analyze and smart auto-completion. The plug-in is also not tested well and may not work perfectly therefore I hope I can get user feedback via mailing list found from Google code development site (listed below). I wish I had time to develop it further. I only develop it in my spare time, which is very limited. I welcome any developers to participate and contribute to the project.
Development site:http://code.google.com/p/llvm4eclipsecdt/
https://github.com/TuononenP/llvm4eclipsecdt
Eclipse marketplace (100% free & open-source):http://marketplace.eclipse.org/content/llvm-toolchain-eclipse-cdt
UPDATE: The plugin is deprecated. Instead install "C/C++ LLVM-Family Compiler Build Support" under Programming Languages using the official Eclipse update site e.g. http://download.eclipse.org/releases/mars
LLVM contributor Dan Gohman recently added Clang code completion to vim.
http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/vim/vimrc is intended for use in developing LLVM itself and helps with the LLVM coding style, but the code completion portion should be easy enough to extract.
Yeah, yeah, vim isn't an IDE, but it may be useful to know about.
[edit] https://llvm.org/svn/llvm-project/cfe/trunk/utils/clang-completion-mode.el provides a similar option for emacs.