Hi All, Just an FYI, I wrote up a somewhat long, rambling, and overdue blog post about the changes to the IR type system here: http://blog.llvm.org/2011/11/llvm-30-type-system-rewrite.html If you haven't done so already, I hope that this helps answer some common questions when moving out-of-tree LLVM API clients from 2.x APIs to 3.x APIs. Comments and questions welcome! -Chris