- Home: https://www.classicuo.eu/
- Inspiration: Ultima Online
- State: beta
- Keyword: role playing, client, clone, content open, multiplayer online + massive
- Code repository: https://github.com/ClassicUO/ClassicUO.git (@created 2018, @stars 287, @forks 193)
- Code language: C#
- Code license: 4-clause BSD
- Developer: 3HMonkey, aclark13, Alias, Andrea Angelini, Benjamin Willard, broxen, c0mput3rxz, deccer, dissident, gaechti, Jaedan, Jakub Linhart, James, jkachhad, Marcelo Paez Sequeira, Mel, Peter Wedder, Plugtopus Agency, Quick, rdegelo, Rob C., roxya, Samuli Yliniemi, Sascha, Siva, Stefan, TannerBist, Timur Alekseenko