Mumble’s version numbers have been a great source of confusion for a long time. Version 1.1.8 being incompatible with 1.2.0, only incrementing the last place of the version number even though big changes were made and so on. This will change.
TL;DR: The next version will be 1.3.0 not 1.2.6. The next feature release after that 1.4.0 and so on.
In practice we used “1.<major>.<minor>” in which the major number is incremented for breaking changes and the minor number for feature releases. This wasn’t actually intended but we were never quite happy with the amount and kind of features we added to actually name a release Mumble 2. Even with the massive and backwards compatibility breaking changes introduced in 1.2.0.
We do realize this is kinda ridiculous so for future releases we will switch to a “<major>.<minor>.<patch>” numbering schema. Major and minor have the same meaning as above while patch is used only for security and bugfix releases like 1.2.5.
This means that the next feature release of Mumble will be 1.3.0 and still will be fully compatible with 1.2.X clients and servers. The next backwards compatibility breaking changes will be in Mumble 2 but there will likely be multiple feature releases before we will feel the need to take that step.
The Mumble team