FOSS gamedev and creative worlds

I need a way to host a server reliably on a local computer that has the ability to use subgames. Any ideas? Also I want to host two worlds at the same time; a survival and a creative super flat. Any ideas on that? Thanks for your time!

Using a dedicated Ubuntu server can be a good idea for maxing out the power of your computer, minetest is avaible in Ubuntu, so there should not be any problem if you know how to set up everything. If you have more knowledge and you think you are ready, you can use a Debian server, which is more complex, but has more advantages if you know how to use them.