In general releases with an even middle number are "stable" while those with an odd middle number are "development." Here are the MD5 digests of recent releases.
The wnssl-2.0 patches were produced originally by Elias Doumas. Recently they were revised and updated by Matthias Cramer. Elias's work was based on previous work of Tim Hudson for the NCSA httpd. Thanks go to all of them.