content: Major Version 0, Minor Version 0, Patch 4. Usually in the Linux world, and what a lot of open source devs practice, x.y.z-dev (sometimes with a svn or git branch identifier) are the unstable versions, and anything with x.y.z versions are stable. A 0.0.z version very well could be just absolute bare bones API and logic to get things working, with more features added and refined at a later date.