The following review written by one of the Software Informer contributors applies to version 3.7
REAPER is a digital audio workstation and uniquely focuses in MIDI recording, editing, processing, mixing, and mastering. It is capable of handling multiple tracks in one single editor.
The program can be customized, users can add as many tracks as they wish, there are no limits. The interface has a Free item positioning, this allows arranging the items vertically over a track.
REAPER features Expand automation. It expands into lanes for editing, and then collapses envelopes back into a single track. Automatic recording modes are handled by track or globally.
This version features import and export with hardware MIDI timing calibration. Also individual MIDI track controls can be added to any track or anywhere else. Another important improvement is allowing getting back to any prior state with a mouse click. VST plug-ins are now supported and have perfect integration even when running 32 bit plug-ins in the x64 version of the program.
Great MIDI editor for a low price with extended features and capabilities. Users will be able to use their imagination and create anything.