A couple of months ago, Martin and I announced a friendly fork of Bazaar, named Breezy.
It's been 5 years since I wrote a Bazaar retrospective and around 6 since I seriously contributed to the Bazaar codebase.
We don't have any grand ambitions for Breezy; the main goal is to keep Bazaar usable going forward. Your open source projects should still be using Git.
The main changes we have made so far come down to fixing a number of bugs and to bundling useful plugins. Bundling plugins makes setting up an environment simpler and to eliminate the API compatibility issues that plagued external plugins in the Bazaar world.
Perhaps the biggest effort in Breezy is porting the codebase to Python 3, allowing it to be used once Python 2 goes EOL in 2020.
Breezy is a fork of Bazaar and not just a new release series.
Bazaar upstream has been dormant for the last couple of years anyway - we don't lose anything by forking.
We're forking because gives us the independence to make some of the changes we deemed necessary and that are otherwise hard to make for an established project, For example, we're now bundling plugins, taking an axe to a large number of APIs and dropping support for older platforms.
A fork also means independence from Canonical; there is no CLA for Breezy (a hindrance for Bazaar) and we can set up our own infrastructure without having to chase down Canonical staff for web site updates or the installation of new packages on the CI system.
Martin gave a talk about Breezy at PyCon UK this year.