A quake engine level editor (likely works with later quake iterations too) rewritten from scratch that aims to replace the GTK Radiant versions with a more modern workflow and focus on 3D view. Mesh handling reminds me a bit of Scetch-Up, which is a great thing as far as I am concerned. Probably makes mapping for Quake engines more Cube2 like (even though it is not in game) and more newbie friendly.
Let's hope they make it Xonotic compatible soon
Edit:
Features
- True 3D editing, no 2D views required
- High performance renderer with support for huge maps
- Vertex editing with edge and face splitting
- Manipulation of multiple vertices at once (great for trisoup editing)
- Smart clip tool
- Move, rotate and flip brushes and entities
- Precise texture lock for all operations
- Smart entity property editors
- Graphical entity browser with drag and drop support
- Comprehensive texture application and manipulation tools
- Search and filter functions
- Unlimited undo and redo
- Point file support
- Automatic backup
- Support for .def and .fdg files, mods and multiple wad files
- Free (as in beer) and open source (GPLv3)
- Cross platform (Windows, Mac OS X and Linux supported)