In order to play, or find out more, just head on over to their main website and download the client. You only require the one program, it has everything else. Just extract it and you are good to go!
When the Cycle begins anew is a great time to join the campaign. Since it’s fresh again for everyone, you are all starting at the same level. MekWars is an online Java-based program that runs a campaign for various players and controls the units you have, repairs, cost, and more. It matches people to play against each other, and then they play using MegaMek. Factions vie against each other, and the results of battles impact the ongoing campaign. So check it out.