For anyone that just wants a post, I'll give some details regarding the engine. Would just like to note that I myself have not used the engine just yet so I don't have any hands on experience.

Stride was initially developed by Silicon Studies. It was first known as Paradox, was renamed to Xenko it seems in 2015 and then renamed again to Stride in 2020. The engine went fully open source under the MIT license in 2018, alongside Silicon Studies stopping their own support. Wiki page source.

Stride is nearly completely made in C# - their Github page lists it at 90.4% C# - and as mentioned above is completely free and open source. They became a member of the .NET foundation in 2021. The editor currently only supports Windows while the runtime Windows, Linux, macOS, Android and iOS. I believe some of the community members are planning a rewrite for the editor to enable stuff like Linux support.

The engine is still being actively worked on by community members, with version 4.2 slated to drop in November implementing .NET 8 support. But it should be noted that the Stride community is no-where near as large as something like Godot, so the pace for larger features is considerably slower.

For anyone that would like to see discussions regarding Stride, the two best sites for Stride are their Github discussions page and their discord (link on their website).

Stuff made with stride can be found on their Made with Stride section. There isn't much YouTube content on Stride outside of their own tutorials, however there was a Ludum Dare Game Jam Devlog posted recently which does give some details on using Stride to develop a game.

If you'd like to contribute to the engine, they have an OpenCollective page for donations. You can also get paid for assisting on the listed projects here, although I'm unfamiliar with how that actually works (more details can be seen on that here). They have said they have had some issues finding people able to assist with these projects, so if they are something that interests you I'm sure they'd appreciate the help.

Popping it down the bottom as it isn't really relevant, but for anyone curious on the named changes. I've heard the Xenko rename was due to the similarity to other companies (like Paradox Interactive), while the Stride rename was due to Silicon Studios not completely giving up the Xenko name (which was blocking them from joining the .NET foundation at the time).