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[edit] The wxWidgets version system

Stable wxWidgets releases (e.g. 2.2.x) refer to versions in which the APIs are guaranteed not to change. Unstable releases (e.g. 2.3.x) are potentially still changing. Note that the stable/unstable designation has nothing to do with amount of bugs. Unstable releases often have more features and bug fixes than stable releases, and may in fact be a better choice for application stability