Unreal Tournament or UT99 is one of those classics that offer a lot of content, far more than what can be found in most modern shooters. Call it nostalgia, but sometimes going back and playing Unreal Tournament (UT99) with some friends can be quite fun. The only downside of Unreal Tournament (UT99) is the outdated graphics.
In order to play Unreal Tournament (UT99) online, you will need to install the most current version of oldunreal from Github. The current GitHub repository is:
https://github.com/OldUnreal/UnrealTournamentPatches
Unreal Tournament (UT99) can be bought from Steam or, if you are old school, you would still have the original CDs. After installation, install the oldunreal from the Github repository above. Before the first match go to the player setup in the preferences tab and set your profile.
After that, go into the multiplayer tab and select Find Internet Games.
All done, enjoy playing Unreal Tournament (UT99) online!