Both use the Open VSX Registry as a marketplace for extensions.
Similar to VS Codium there’s also Eclipse Theia.
Looking at this video: https://www.bbc.com/news/av/world-asia-48476879, it seems they did succeed to erase the Tiananmen events from Chinese memories…
There are plenty of FLOSS alternatives: https://alternativeto.net/software/microsoft-to-do/?license=opensource
There’s a thread that lists some FLOSS StackOverflow alternatives here: https://lemmy.ml/post/38944
I selfhost a Miniflux instance