Gaming

osu!lazer

Dungeon Crawl Stone Soup for me. A classic roguelike with active community and regular updates as well as several forks. It also has a good amount of playable races. From classics like elfs or orcs ~~and dwarves~~ (RIP Mountain Dwarves you were too good for this game) to funky races like Vine Stalkers (sentient parasitic plants) and Armataurs (centaurs but with armadillo parts instead the horse ones) to cats and octopuses.

And the gods you can worship in the game are also very diverse. How about a slime god? Or someone who wants you to wear as much cursed equipment as possible in exchange for knowledge? Or maybe the one who wants everything to move veeery slooow and rewards you for killing mobs that are faster than you?

Arguable if you can call it a game or not, but there is Overte. It is an open-source social VR platform. (without crypto so please no pitchforks)

As one of its developers I might be biased, but I wouldn't be one of the developers if I didn't honestly believe in the project.

Minetest!

https://www.minetest.net/

Not quite what you are asking for, but here's a list of source ports of commercial games, most of which have Linux ports.

Oh and I'll single out The Ur-Quan Masters as an older source port of Star Control II. Old enough that the port itself is nostalgic for me, although it's still being updated by the looks of it.

I'd say Pokemon Infinite Fusion. It's written in Rails and the artwork is done by the community

Only one that comes to mind is Lugaru. The creator had this weird legal battle where someone stole the game, ported it to iOS, and the thief claimed because it was open source he was allowed to sell it.

Thanks for the Veloren recommendation, I liked Cube World, it just didn't work out well.

I used to play openarena (Q3a ish) a lot. And we had some group games of freeciv. I never got torcs to work well enough to play. That would have been great and simulation would be the perfect kind of "game" to free / open source. And countless hours of nethack on every platform I had (which was a few). Other roguelikes too. Ones that actually are like rogue, that is. Even rogue.

But all that was a long ago. Should maybe explore more.

If you're into strategy games, OpenTTD! https://www.openttd.org/

It's an open-sourced Transport Tycoon Deluxe, and it never gets old for me!

Cockatrice for playing TCGs / CCGs online.

Does City of Heroes count? It was closed source but was opened...

For me it's CDDA, a quite realistic and deep apocalyptic survival game with very frequent updates(on the experimental branch)

There's so many, from the ones I played and come back to often: InfraArcana, Battle of Wesnoth, Cataclysm: Dark Days Ahead (and it's variants: Bright Nights, There Is Still Hope).

One of my absolute favorite games as a kid was Glest. Turns out it's open source and is now available as MegaGlest!

It takes a lot of inspiration from Warcraft but it has its charm and many of the races are quite unique in how you play them!

Terminal games:

Adventure - A classic adventure game. (In the BSDGames package) Hack - The game that inspired NetHack. (In the BSDGames package) Greed - A game where you go through a number field, eating the numbers. It's hard to explain but very fun. Rouge - It's nice to go back to the classics. I like Hack a bit more though.

Non-Terminal Games:

Secret Maryo Chronicles - It's like Super Mario Bros. Alien Arena - Kind of like natural selection. Urban Terror - Kind of like Counter-Strike Warsow - Kind of like Quake. Xonotic - Like Quake again.

I think that's all I played back in the day.

[](Dungeon Crawl Stone Soup)

@Vitaly I highly recommend SRB2Kart, i think it is the best kart racer.

for some reason it is always overlooked when open source games are being discussed.

(https://mb.srb2.org/addons/srb2kart.2435/)