- Change license from LGPL 2.0 to Apache 2.0
- Port to Python 3 with support for 3.5, 3.6, and 3.7
- Python < 2.7 is no longer supported
- Port from GTK+ 2 and PyGTK to GTK+ 3 with PyGObject
- Migrate tests from Nose to PyTest with Tox
- Reorganize project files
- Overhaul the README
- Add contributing guide and code of conduct
- Adopt Black as code formatter
- Add Continuous Integration with Travis and Read The Docs