High Quality Content by WIKIPEDIA articles! MTASC (Motion-Twin ActionScript 2 Compiler) is an ActionScript 2.0 compiler written in the Objective Caml (OCaml) programming language by the company Motion-Twin. It is free software and can be used alone or with other tools like swfmill to produce SWF files, which contain interactive multimedia content playable with the Flash Player. MTASC is also much faster than the Adobe Flash ActionScript compiler.