Hello, I've recently released version 1.0 of extcore, a library for processing code in GHC's text-based External Core format. extcore includes a parser, prettyprinter, typechecker, and interpreter for External Core, as well as modules for computing module dependencies and combining multiple Core modules into a single module. The library was originally written by Andrew Tolmach and was part of the GHC distribution. After becoming its maintainer, about a year ago I moved the library to Hackage. Since in the past year, the library has acquired some users but has received no fatal bug reports, I thought it was time for a 1.0 release. You might be interested in using this library if you're a compiler or tool writer who wants to write a tool that processes the output of GHC's front-end and simplifier -- that is, code in the Core intermediate language, a typed functional language in which many of Haskell's features have been desugared into a polymorphically typed lambda-calculus (extended with type coercions, as are necessary to support type system features such as GADTs). Such tools might include alternative back-ends or new program transformations. Using the extcore library allows tool writers to experiment with implementing new compiler features without modifying GHC itself. While the GHC API is also a route to adding new stages to the GHC pipeline, using extcore has the advantage that External Core is well-specified (read on) and less subject to change than GHC's internal Core format. The library has been tested on External Core produced by GHC 6.10.* and GHC 6.12.*. It has not yet been tested on External Core produced by GHC 7.*. Documentation for the External Core format itself lives at http://www.haskell.org/ghc/docs/latest/html/ext-core/core.pdf - but documentation for the library is limited, and I would welcome documentation or other patches. Currently the best source of documentation for the library is the README file, found in the distribution. To get the distribution, please visit http://hackage.haskell.org/package/extcore or cabal install extcore. Please direct replies to glasgow-haskell-users@haskell.org, with me CCed. Please make sure not to reply to haskell@haskell.org. Cheers, Tim Chevalier -- Tim Chevalier * http://cs.pdx.edu/~tjc/ * Often in error, never in doubt "an intelligent person fights for lost causes,realizing that others are merely effects" -- E.E. Cummings