MapServer's version numbering scheme is very similar to Linux's. For example, a MapServer version number of 4.2.5 can be decoded as such:

• 4: Major version number. MapServer releases a major version every two to three years.
• 2: Minor version number. Increments in minor version number almost always relate to additions in functionality.
• 5: Revision number. Revisions are bug fixes only. No new functionality is provided in revisions.

From a developer's standpoint, MapServer version numbering scheme is also like Linux. Even minor version numbers (0..2..4..6) relate to release versions, and odd minor versions (1..3..5..7) correspond to developmental versions.