Glyphs vs UFO?

[davelab6]

The sources are provided in both Glyphs and UFO; however, which is the format actually used for development?

Now that https://github.com/googlei18n/glyphsLib provides a bridge from Glyphs source files (.glyphs) to UFOs via defcon, providing duplicate sources seems unnecessary :)

[Artoria2e5]

Judging from the only branch it appears that Glyphs is the main one.