Dear Haskellers, Many months after the topic was first raised, there is finally a draft document describing a formal external syntax for GHC's "Core" intermediate language. It is available from http://www.cs.pdx.edu/~apt/ext-core.ps Those who wish to experiment seriously with the format described can download the latest "HEAD" experimental version of GHC. Using the "-fext-core" option when compiling "foo.hs" will generate a file "foo.core" (in additition to any other outputs specified). The document currently gives only an informal semantics "Core;" a much more formal semantics -- which I view as a very important thing to have in practice -- is in progress but not quite ready for public scrutiny. As this is very much a draft (you'll see the holes!), feedback is welcome, but due to the GHC-internals nature of this topic, please direct your comments to glasgow-haskell-users@haskell.org or to me personally at apt@cs.pdx.edu. I'll be out of email contact for the next month, though, so don't expect replies until July! - Andrew Tolmach