Digital Performer was the last to run on Mac OS 9, the Classic Macintosh operating system. After a complete rewrite, MOTU released Digital Performer 4.0 in May 2003, which ran exclusively on Mac OS X. Beginning with version 4.5, MOTU introduced a number of important new features to Digital Performer. The two most important of these are built in pitch correction capability, and the professional Masterworks EQ plugin. Beginning with version 5.0, MOTU also introduced a set of virtual instruments. The software was updated to version 5.13 on 19 November 2007 to provide compatibility with Mac OS X v10.5. and available in Universal Binary. Version 7.2 was introduced in 2010. Digital Performer remains one of the popular audio workstations on the Macintosh. Faster Apple CPUs continue to increase its capacity and performance. Chief among its competition on the Macintosh platform are Pro Tools and Apple's Logic. In October 2012, MOTU released Digital Performer 8 for OSX. Digital Performer 8 is available on Windows as well. Version 9 of Digital Performer was released in June 2015 for Mac OS X and Windows. This version contains workflow enhancements, some new effect plugins, including emulations of the 1176 Peak Limiter and Craig Anderton's MultiFuzz. MOTU also included a 64-bit version of its software synth (synthesizer) MX4 which used to be sold as a stand-alone product. Version 10 of Digital Performer was released in February 2019 for Mac OS X and Windows. This version includes a new 5 GB instruments soundbank, a time/pitch audio stretching feature, and a real time loop triggering function. AudioDesk AudioDesk is a more basic version of MOTU's Digital Performer for mac only. It is a multi-track recording, editing, and mixing application, with both offline file-based processing and realtime effects. Much of the graphical user interface (GUI) and its operation are similar to Digital Performer, although it lacks some of Digital Performer's features. Most notably, it does not include MIDI sequencing capabilities, and thus does not include some of Digital Performer's MIDI-specific editing windows. Also, AudioDesk is only available as a bundled application with MOTU audio interfaces; this also means that AudioDesk requires a MOTU audio interface to be used as its soundcard. AudioDesk version 1 was first released in 1998, as bundled software with the MOTU 2408 PCI-based audio interface. Version 1 is compatible with the Classic Mac OS. Version 2 for Mac OS X was released in 2003,