Post Description

Audio
REAPER's no-compromises 64-bit audio engine and 64-bit end-to-end signal path offer the maximum in resolution and headroom. Unlimited track counts, total routing freedom, draggable sends, beat-based audio templates, sidechain support for any plugin - REAPER gives you both power and flexibility. 

MIDI
REAPER doesn't discriminate against MIDI. You can freely mix audio and MIDI routing, even within a single track. REAPER's parameter modulation allows you to creatively sidechain midi and audio: drive your synth's cutoff filter with an audio signal, or create midi triggers with an audio gate. You can even script your own JS MIDI processing plug-ins and customized game controller-to-MIDI support! 

Everything You Need
REAPER includes over a dozen top-quality 64-bit ReaPlugs, the celebrated Elastique 2 real-time pitch-shifting engine, full REX support, and literally hundreds of user-programmable effects. Run almost any VST, DX, or AU (OSX only) plug-in, or use the included JS audio and MIDI plug-in scripting engine to create your own. 

Nothing You Don't
REAPER's 4MB download is smaller than some web pages. It contains no multi-gigabyte library of someone else's music, no crippled evaluation versions of a bunch of software somebody paid us to package, no arbitrary hardware or software restrictions and absolutely no invasive copy protection system.