There's an interesting potential future here where Apple acquire/acqui-hire the team behind this. As much as I'm keen to see software like this, making an edit

There's an interesting potential future here where Apple acquire/acqui-hire the team behind this. As much as I'm keen to see software like this, making an editor work as a business is hard, and Zas has a long road ahead of it. However Apple could really use something like this. Xcode is big and bloated, with a ton of support for features that are no longer the future of Apple's platforms (Storyboards, Objective-C, SVN integration...). A clean start with a modern codebase designed for languages fairly similar to Swift, plus the shift towards Swift Package Manager for managing builds (rather than xcodebuild), could be great improvement.