I still plan to add more features: reactivity for mutable objects, custom viewers, general extensibility and performance improvements. For the most part the ux should remain similar. I haven't used REBL a lot so I'm not sure how to compare. Are there specific issues you are worried about?

Portal is usable for daily development as I use it every day for work. Before every release, I go through a series of regression tests to ensure things still work.

thanks for the response! no, no specific issues.

i saw the demo, it looks great. i'm excited to try it out

While I can't speak to its maturity compared to rebl, it is definitely stable enough. I also use it daily at work. It's a fantastic tool, especially for large data structures! Shadow-cljs has its tap inspector for free, but I always reach for portal instead. It's much easier to use and parse data with.