At least they tried.
Many of these have public, archived repositories, differently from hundreds of dead Google projects.
Seeing “the source is available here on GitHub”, “the project was forked and is now maintained as (other name)”, etc. after most of these really helps show the difference with Google. Well that and the length of the article, Google has far more deaths under their belt.
Twenty things Mozilla the company killed and they didn’t mention ITS OWN NAMESAKE APP. It’s didn’t ‘evolve’ into Firefox: they split the baby in half and cut away the connective tissue.
A forgotten one is webassembly.studio, an in-browser IDE for creating WASM projects with way less pain than other methods. It got discontinued the year I needed it for my school project. It was open source but I failed to rehost it myself and public mirrors only appeared after I spent days trying to make Emscripten work, tore my hair out over WebGL and then finally painfully built the whole thing with CSS (and a bit of JS; yes, it was indeed a disaster).
Imagine my disappointment when I realized “Firefox advance” wasn’t for the Gameboy advance :(
I felt the firefox send death, used all the time to share quick files with friends, thankfully I discovered litterbox after they killed it.
There’s also https://send.vis.ee/