Hey Robby, Yeah, two documents: The "PVP" http://www.haskell.org/haskellwiki/Package_versioning_policy The Package Addition Policy for the Haskell Platform http://trac.haskell.org/haskell-platform/wiki/AddingPackages robby:

Hi all. Just thought I'd poke my head in here (perhaps where I'm not wanted...) to ask: is there a rationale and/or guidelines for how to use version numbers in hackage somewhere that I could read?

I ask because we worry that similar things to this discussion would come up in PLaneT, the Racket package management scheme (if you're curious see http://planet.racket-lang.org/ for the site or http://docs.racket-lang.org/planet/index.html for the documentation).

We preemptively resolved this kind of thing by tweaking the semantics of version numbers. Specifically, if you ask for version 1.3, say, of a package, PLaneT will give you the largest version that has the same major version number, ie the largest 1.x (that is compatible with the version of Racket you're using, that is). The idea was that when changes to the functionality happen, the package maintainer would bump the major number and feel safe that old uses would not break. This seems to have worked pretty well in practice, fwiw (PLaneT has been around for six years so far).

(We took inspiration for this particular issue by the way we've seen major version numbers move into package names in various linux distributions.)

Robby