Hi All,
LLVM 2.1 is done! Download it here: Download LLVM releases or view the release notes: http://llvm.org/releases/2\.1/docs/ReleaseNotes\.html
The LLVM 2.1 has many improvements, including three new front-ends, a huge reduction in -O3 compile times, a new (beta) MIPS backend, and many optimizer/code generator changes that allow LLVM to produce better code. In addition to new features, LLVM 2.1 includes a large number of bug fixes found by compiling a huge number of applications, OS kernels, and very large open source projects.
Organizationally, the LLVM 2.1 cycle is memorable for several reasons. In this release we switched from CVS to SVN, moved llvm-gcc to the main LLVM server (it used to be in a private repository which was mirrored publicly once a day), and grew the community very rapidly: we added many new commiters. Another interesting metric is the the main LLVM repository (not counting llvm-gcc or other separate projects) crossed 500,000 lines of code: http://llvm.org/nightlytest/locgraph.php?xsize=900&ysize=600 .
One of the highlights of this release cycle was the ability for many of us to get together to meet face to face at the 2007 LLVM Developer Meeting: The LLVM Compiler Infrastructure Project . If you're interested, many great talks about LLVM are available on that page, including a great section where everyone introduces themselves to the world :).
In the end, the most exciting thing about the LLVM project is seeing all the ways that people apply the technology and having happy users. If you're currently using LLVM for nifty things (http://llvm.cs.uiuc.edu/Users.html) or are writing papers (The LLVM Compiler Infrastructure Project), please let us know. Over this release we added a number of interesting publications, but I am certain that we're missing some. If you're using LLVM please let us know - it's free advertising for you and your work. 
Instead of including a list of the major features in this announcement as I normally do, I'll point you to the LLVM 2.1 release notes [ LLVM 16.0.0git Release Notes — LLVM 16.0.0git documentation ] which includes the high-level items.
This release wouldn't be possible without many people in the LLVM community: building new features, reporting bugs, testing the pre-release bits, and contributing in many other ways. Tanya deserves many thanks in particular for doing a great job with release management, which is often a thankless task.
If you have any questions or comments, please contact the LLVMdev mailing list (llvmdev at cs.uiuc.edu)!
-Chris
Previous Announcement (LLVM 2.0):
http://lists.cs.uiuc.edu/pipermail/llvm-announce/2007-May/000023.html