In Lazygit Turns Five[0], the author mentions Jujutsu[1], which seems to be an effort to create a Git v2 that addresses some of the awkward edges of the initial implementation. I'm really interested in learning about similar efforts in other domains (i.e. video/audio transcoding, operating systems, programming languages, etc). Specifically, I'm curious about efforts that are roughly <= 5 years old and were initially started as individual projects. One example that (mostly) fits this category for me is Zig[2].
[0] https://jesseduffield.com/Lazygit-5-Years-On/
[1] https://www.youtube.com/watch?v=bx_LGilOuE4
[2] https://en.wikipedia.org/wiki/Zig_(programming_language)