Reason is a digital audio workstation for creating and editing music and audio developed by Swedish software company Reason Studios (formerly known as Propellerhead Software). Reason emulates a rack of hardware synthesizers, samplers, signal processors, sequencers, and mixers, all of which can be freely interconnected in an arbitrary manner. Reason can be used either as a complete virtual music studio or as a set of virtual instruments to be used with other sequencing software in a fashion that mimics live performance.
Reason 1.0 was released on November 22, 2000. The program's design mimics a studio rack into which users can insert virtual devices such as instruments, effects processors, and mixers. These modules can be controlled from Reason's built-in MIDI sequencer or from other sequencing applications such as Pro Tools, Logic, FL Studio, REAPER, Digital Performer, Cubase, Sonar, and GarageBand via Propellerhead's ReWire protocol in the 32-bit versions of these programs. Since the release of version 6 Reason supports ReWire with 64-bit hosts.