Hello, What is protocol-buffers? Google's "..language-neutral, platform-neutral, extensible way of serializing structured data for use in communications protocols, data storage, and more." http://code.google.com/apis/protocolbuffers/docs/overview.html What is Haskell protocol-buffers? This provides a program 'hprotoc' which compiles a ".proto" file defining messages to Haskell modules, and the protocol-buffers API to access them and convert back and forth to the binary wire protocol, and protocol-buffers-descriptors which are messages which describe ".proto" files and allow for runtime reflection of annotated message definitions. The big addition to this version (which is 1.4.0) over the previous version (which was 1.2.0) is for when modules are in a dependency loop. The most common reason this happens is whenever a message is extended in the same proto file but outside of the message itself (e.g. at the top level). This was salved in previous versions by telling the user to create boilerplate header files (a .hs-boot file) and add a few {-# SOURCE #-} pragmas. This was primitive, and could not cover all the corner cases. Those days are gone. The new version of hprotoc uses the cutting edge version of haskell-src-exts (4.8.0) to generate not only the Haskell modules but also the hs-boot files and {-# SOURCE #-} pragmas! This is truly a glorious way to start the New Year. But wait, there is more! If a more than two messages define extensions of each other in a strongly connected dependency graph then the hs-boot files are not enough. For these strange cases hprotoc will now generate modules ending with 'Key.hs that separately define the extensions. You do not need to lift a finger, you never need to import these modules yourself, this all exists behind the scenes. Also, hprotoc goes way out its way to reduce the number of .hs-boot and 'Key.hs files, and it uses only a minimal set of {-# SOURCE #-} pragmas. It is so painless that if I did not put this into this announcement you might not even know. Now all generated should compile with no changes or additions. Of course, hprotoc still generates nothing for services and methods. Where to get the new shiny packages? hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/protocol-buffers http://hackage.haskell.org/cgi-bin/hackage-scripts/package/protocol-buffers-... http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hprotoc And you will need haskell-src-exts, version 0.4.8, by Niklas Broberg: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/haskell-src-exts-... (past version do not work and future versions will probably change enough to break compilation of hprotoc) Happy New Year, Chris Kuklewicz