Release number tuple
The Wireshark release numbers are constructed as a three number tuple: Major.Minor.Maintenance.
The Major release number has reached 1 after numerous years of development and is likely to remain that way for a while. Only when the program undergoes a significant change this number will increment.
The Minor release number basically follows an even/odd number scheme. For every official release an even number is assigned and the code is branched off for maintenance. The development continues on the next higher odd release number. Note that this development package is a moving target and meaningless without its subversion revision number.
The Maintenance release number gives you the stage of maintenance which that release is in. It starts of with 0 and increments with every maintenance release.
Before a release there may be prereleases, which are designated as such.
Example release number tree
This tree shows a release number assignment tree based on this algorithm. On the left the development tree is visible, while to the right the stable releases grow out. It's is like an upside down tree.
Ethereal | v +--> 0.99.8pre1--> 0.99.8 | v 0.99.9 | +--> 1.0.0pre1--> 1.0.0pre2--> 1.0.0--> 1.0.1--> etc | v 1.1.0 | v 1.1.1 (If we have the need for an intermediate development version number) | +--> 1.2.0pre1--> 1.2.0pre2--> 1.2.0--> 1.2.1--> etc | v 1.3.0 (if this development significantly changes the program the Major number may bump) | +--> 2.0.0pre1--> 2.0.0.pre2--> 2.0.0--> 2.0.1--> etc | v 2.1.0 etc