https://github.com/haystackeditor/haystack-editor
It's still probably the best tool to navigate, visualize and understand complex codebases, which is particularly important now with AI coded repos. I keep looking for alternatives but they are all notably worse.
About a month ago I spent a few frustrating hours building it from source for my system and making it work, and I've enjoyed using it as my main IDE since.
I wish I had the time to make a fork and bring in a newer version of VSCode. If anyone takes it up I might help at least.