: Ok i know there are other posts and things about this but i still got some
: big questions.
: How to play Marathon online?!
To play the original Marathon online requires some weird programs like NetLink Plus and a modem to dial out over and... it's not how anybody plays anymore anyway so don't bother.
What you want is Aleph One, the new Marathon engine based on the open-sourced Marathon 2 code. This will allow you to play both Marathon 2 and Infinity online (and also with OpenGL graphics and a lot of other nifty stuff). Just put a copy of Aleph One in your M2 folder or your Infinity folder and open that instead of the original Marathon 2 or Marathon Infinity programs.
For Marathon 1, however, the file formats are different so you can't just do that. You'll need to grab M1A1, which is "Marathon One for Aleph One". You can nab it off of FileBall (you want the version that's not "SDL", since you're on a Mac). M1A1 is basically a total conversion of Marathon 2 / Marathon Infinity back into... Marathon 1. Download it, put a copy of Aleph One in that folder, and there you've got Marathon 1 in Aleph One.
For any of these games, you join an internet game by going to the Join screen like you would a normal local network game, but you want to "Join by IP" and punch in the address of the person who's hosting the game. You can meet these people, most often nowadays, on the Forerunners Hotline server. Grab this program, and connect to the server hl.forerunners.org. You don't need a username or password. The people there would be happy to play a game or ten with you, and also help if you have any other questions.
There is also theoretically a metaserver, a place where you can log in and see other players and games in progress and chat before a game, but I don't have any experience with that and I believe it's presently not working anyway, so it's probably best to find somebody on Hotline and join a game with them.
