From Claws Mail FAQ
Claws Mail Development Model
Stage 0: Release of a new .0 version Stage 1: Propose ideas/goals Stage 2: Implementation, single developer testing and committing to CVS. Fix reported and discovered bugs. Stage 3: Synchronization and multiple developer (and CVS users) testing, unless the code is mature enough, go to stage 2 (or 1). From time to time, migrate bugfixes to stable branch. Stage 4: Depending on the goals reached, code maturity, moon phase and other variables, release a stable bugfix, a beta, or a rc. Stage 5: Magic happens here. Stage 6: Feature freeze (usually 2 weeks before 8). Stage 6b:Fix bugs. Stage 7: String freeze (usually 1 week before 8). Stage 8: Release a new shiny version.
Motto: All of this can change at developers will. Code must flow.