Basic features:
- Portable - supports running from USB keys or other removable media
- 64 bit audio engine
- Excellent low-latency performance
- Multiprocessor capable
- Direct multi-track recording to many formats including WAV/BWF/W64, AIFF, WavPack, FLAC, OGG, and MIDI.
- Extremely flexible routing
- Fast, tool-less editing
- Supports a wide range of hardware (nearly any audio interface, outboard hardware, many control surfaces)
- Support for VST, VSTi, DX, DXi effects
- ReaPlugs: high quality 64 bit effect suite
- Tightly coded - installer is just over 2MB

Editing features:
- Tool-less mouse interface -- spend less time clicking
- Drag and drop files to instantly import them into a project
- Support for mixing any combination of file type/samplerate/bit depth on each track
- Easily split, move, and resize items
- Each item has easily manipulated fades and volume
- Tab to transient support
- Configurable and editable automatic crossfading of overlapping items
- Per-item pitch shift and time stretch
- Arbitrary item grouping
- Markers and envelopes can be moved in logical sync with editing operations
- Ripple editing - moving/deletion of items can optionally affect later items
- Multiple tempos and time signatures per project
- Ability to define and edit project via regions
- Automation envelopes

REAPER 3.60 - June 10, 2010. Changes:

* OSX:
o much faster graphics updating (thank you, Apple, for your fantastic documentation)
o better edit cursor displays (matches Windows)
o fixed mouse option for mousewheel to target window with focus
o menu shortcut display support for control key modifier, other special keys
o faster configuration file access
o fixed action to reset all MIDI devices crashing on some MIDI devices
o default text drawing is now faster
* Transport:
o show editable playback tempo and time signature
o mousewheel adjust play rate, tempo, selection start/end/length
o alt+mousewheel to adjust time selection by beats
o mousewheel over time selection length to move the entire selection
o theme images for BPM tap-tempo button (transport_bpm, transport_bpm_bg)
o theme images for playspeed and selection edit fields (transport_group_bg, transport_edit_bg)
o theme images for status box (transport_status, transport_status_err)
* Action:
o go to marker 11-30
o reset soft takeover for all MIDI controller assignments
o unselect all tracks, items, and envelope points
o adjust all tempo markers at once by various units
* MIDI editor:
o fixed grid snapping when project contains odd-length time signature changes
o action to toggle locking MIDI item to fixed tempo, or follow project tempo changes
o fixed grid snapping, note insert length when MIDI is locked to a fixed tempo
o optimized edit cursor display
o update toolbar step sequencer buttons on enable/disable
* Nudge/Set:
o move items by precise time/beat/sample/frame/selection units
o move cursor or copy items by precise units
o actions to nudge left/right by last nudge dialog settings
o actions to save/recall up to 8 configurations (assign to shortcuts or toolbars)
* Video:
o added "Video window follows edits" setting in Prefs>Media>Video
o muted items, muted tracks are not displayed
o FFmpeg: added YV12 and YUY2 colorspace decoding support (makes video decoding faster)
o FFmpeg: bundled OSX versions are now 10.4+ compatible
o FFmpeg: improved video frame display when seeking during playback
* Keyboard entry:
o preference to disable applying typed-in edit changes after 1 second (in some places)
o cancel changes on escape, commit changes on tab or enter key (in some places)
* Media explorer:
o action to show source properties for current media preview (right-click preview display)
o unload stopped preview media if user preference is to offline media when switching away
* MIDI file writing:
o more compatible ASCII conversion for some UTF characters
o new option to write text events as UTF-8 (preferences/media/MIDI)
* Tempo:
o more efficient rebuilding of complex project tempo maps when adjusting tempo quickly
o better multithreaded time map access (faster tempo information delivery to plugins)
o tap tempo creates only one undo point
* Tooltips:
o fixed occasional stuck tooltip on certain mouse movements
o many tooltips now also appear in main info box
o simplified tooltips that appear when moving media items
* Winamp visualization plug-ins:
o default option to disable WA plug-ins completely
o various bug fixes
* Accessibility: expose basic track, envelope, transport control to screen readers via MSAA
* API: added GetMasterTrack
* Batch converter: better support for unicode filenames
* Custom menus: much faster import of menus and menu sets
* Envelope control panels: respect global UI scaling preference
* Export: automatically prevent trim/convert on REX and video files
* FX browser: renaming item preserves selection, and resorts
* MIDI items: fixed source properties reported media item length
* Mixer: show MIDI hardware outputs in send/hardware output list (themable: mcp_sendlist_midihw)
* ReaEQ, ReaDelay, ReaPitch, ReaXcomp: correct automation behavior when adding/removing bands
* ReaScript: x64 Python support
* Relative snap: fixed occasional reset of item snap offset
* Selection sets: actions to save/load up to 10 sets of item selections
* Solo defeat: receives are always audible even if source tracks have sibling solo
* Startup: faster
* Time selection: preferences to clear time selection and/or loop points by clicking ruler or arrange view
* Trim behind items: support toggling on/off within custom actions
* Windows: fixed file open issues on pre-XP operating systems