UPDATE: XBar is a reboot by the original creator of BitBar [2]. I understood it as I was confused why I have it in my starred. The below is my analysis before I understood it.

UPDATE 2: The authors of both also were considering to merge the projects. [3]

I see XBar seems to be more advanced and more popular.

It has these Advanced APIs like URL schema [0].

and also the GUI for plugins compared to Swiftbar

The tech stack of course is also much different as it's written in Go and Swiftbar as the name applies in Swift.

Although I like that SwiftBar has cron syntax support [1]. I didn't find a similar function in XBar.

A comprehensive comparison in one or the other's repo README could be useful

[0]: https://github.com/matryer/xbar#advanced-apis

[1]: https://github.com/swiftbar/SwiftBar#refresh-schedule

[2]: https://github.com/matryer/xbar/issues/607

[3]: https://github.com/matryer/xbar/issues/607#issuecomment-7752...

I was wondering about why SwiftBar existed when there was already BitBar, and a lot is explained in this thread on Github: https://github.com/swiftbar/SwiftBar/issues/95

TL;DR: BitBar stopped working well in Big Sur and the old code base was increasingly hard to update and build.

This was the first question that came to mind for me too.