MAX / MSP 4.5.7
Max is a graphical development environment for music and multimedia developed and maintained by San Francisco-based software company Cycling '74. It has been used for over fifteen years by composers, performers, software designers, researchers and artists interested in creating interactive software.
The Max program itself is highly modular, with most routines existing in the form of shared libraries. An API allows third-party development of new routines (called "external objects"). As a result, Max has a large userbase of programmers not affiliated with Cycling '74 who enhance the software with commercial and non-commercial extensions to the program.