OpalVoip uses the "even is stable, odd is development" version numbering scheme popularised by the Linux kernel.
PTLib and OPAL are separate libraries, and hence use different version number sequences. To avoid confusion, we tend to make new releases of both packages at the same time to keep the version numbers in lockstep.
The odd numbered development stream is also marked "alpha" when you get version numbers strings from the libraries. The even numbered stable versions are "beta" in the SVN branch. Only the formally released tar balls, and their associated "tagged" SVN versions do not have "alpha" or "beta" associated with them.
The releases of OPAL/PTLib are:
For information on the naming system, see this page
Change logs for each released version are here.
Tarballs and ZIP files of all stable versions and selected development versions are available on the SourceForge download page.
See this page for information on Source Forge Subversion access.
Compatibility with OpenH323 releases
Revision 2.0 of PWLib is identical (except for packaging differences) to the 1.12.0 release of PWLib available from the OpenH323 web site.
Revision 3.0 of OPAL is identical (except for packaging differences) to the 2.4.0 release of OPAL available from the OpenH323 web site.