Duncan and I have started a wiki page to collect proposals for ways to avoid or alleviate the pain from future package reorganisations. http://hackage.haskell.org/trac/ghc/wiki/PackageCompatibility It's been helpful for me to write all this down, the issues seem much clearer. However, I don't see an obviously best solution. For me proposal 4.2 (see the wiki page) looks the most promising, but it doesn't provide complete backwards compatibility, so I imagine there will be people who disagree. Please read the page. Fix problems, add rationale, add proposals if you have any that are substantially different from those already there. For general discussion just reply to this message (replies directed to libraries@haskell.org). Cheers, Simon