From website:

The Widelands Development Team is proud to announce the immediate availability of the stable release Widelands 1.2.

Since the release of version 1.1, we implemented several hundreds of new features and bugfixes; for example, to name just a few of the highlights:

UI Plugins are add-ons that can add more functionality to the user interface
Naval Warfare preview: Invade foreign coasts using warships!
This is included as a preview feature and needs to be explicitly enabled in the game setup screen.
Soldier garrisons for ports and headquarters
Balancing changes to the Amazon economy
Fifth scenario for the Frisian campaign
More settings in the game setup screen, such as configurable durations for timed win conditions
Diplomacy handling for the computer players
Stick pinned notes onto map fields to mark important points
Hyperlinks let you navigate within the encyclopedia and to the online help
Easy maps publishing inside the editor
High-resolution images for many more units
Accessibility enhancements for many user interface components
Expose more functionality to the add-ons and scenario scripting interface
Fixed many crashes and hangs and enhanced error handling