M.U.G.E.N is a 2D fighting game engine designed by Elecbyte, functioning off of user-created content such as characters, motifs and screenpacks. The engine takes its name from the Japanese word 無限 (lit. 'limitless' or 'infinity').
I.K.E.M.E.N is a 2D open-source engine that supports M.U.G.E.N content, and also what I work with.
I personally make Screenpacks and Compilations and SOMETIMES i'll make a stage lol.