Gibson Guitar Corp. has released the Opcode music sequencing applications, Vision DSP 4.5.1 and Studio Vision Pro 4.5.1, as freeware, reports Both titles were released in the summer of 1999, and as such Gibson recommends using Mac OS 8.6 or earlier; Mac OS 9 compatibility is unclear. Also released as a free download is OMS, which enables user control of MIDI devices in Mac OS 8/9 applications.