Valve is solving the chicken-and-egg problem. For a developer, it is costly to maintain a separate build for Linux without the consumer base to justify the effort. And without games, most people will not leave windows.

Proton offers Valve independence from windows without effort and cost for the developers. And without penalties for the gamers as well.

I remember that was an issue discussed in the first days, not sure how big of a problem after that though.

Btop?

A voting counter for 3 voting systems. It was a rewrite of a code I wrote some years prior, and the cool factor was to feel that the new version was trustworthy even before writing the tests.

I also made some specialized chatbots, good results.