http://nuclearcdboxafziza4mgohcwhzfjiyg6zeslnry33pepsgtur2wyeyd.onion/social/thread/69.html
Many of them are already popular, including Firefox, VLC, 7-Zip, Krita, Blender, Godot, Audacity, OBS, Handbrake, LibreOffice, Linux operating systems (instead of Windows/Mac) and the Android base system.
On top of tools for your own computer, many online services are based on FOSS, including Mastodon and Lemmy instances, the many tools at https://disroot.org/en/#services and even Nuclear Change (running fusion, a fork of jschan imageboard...