StriderX's Mugen Page
Creator of Heavyarms
Cabbit Mugen
Other home of Heavyarms(same Heavyarms), has a bunch of hosted characters.
Brent's Mugen Creations
Creator of Tallgeese
NodeX's page
Creator of Sandrock
Ranmasama's Mugen page
Creator of Shenlong
Mouser's Mugen page
Creator of Wing, Mercurius, and Deathscythe
Mugen X°
Creator of the other Deathscythe
Mugen Developement Forum
In my opinion, the best, and most used MUGEN forum. On it, my username is Steal 2
Mugen Showdown
A good website that has MUGEN news
ShinRyoga's Page
The creator of Mario and has a Bowser WIP.
