I like semver. My favorite part is point 12: Precedence MUST be calculated by separating the version into major, minor, patch, pre-release, and build identifiers in that order. Major, minor, and patch versions are always compared numerically. Pre-release and build version precedence MUST be determined by comparing each dot separated identifier as follows: identifiers consisting of only digits are compared numerically and identifiers with letters or dashes are compared lexically in ASCII sort order. Numeric identifiers always have lower precedence than non-numeric identifiers. Example: 1.0.0-alpha < 1.0.0-alpha.1 < 1.0.0-beta.2 < 1.0.0-beta.11 < 1.0.0-rc.1 < 1.0.0-rc.1+build.1 < 1.0.0 < 1.0.0+0.3.7 < 1.3.7+build < 1.3.7+build.2.b8f12d7 < 1.3.7+build.11.e0f985a. (No non-lexicographic comparisons). Unlike PEP-386 it would also allow DVCS revision ids to be included in the version string. Taking a look at pypi, ~1k of the latest releases do not parse as semver (if you extend it by making 1.0 equivalent to 1.0.0, as all semver versions have at least (major, minor, patch)). This is similar to the number of latest package versions that don't parse as PEP-386. I also found this blog post. http://blog.ziade.org/2009/07/03/dropping-pep-386-versions-comparison/ How much would it cost to endorse semver? Daniel H