Cockos has updated the Windows version of REAPER to v2.14159 and also recently posted a new Mac OS X preview build (v0.72).

Changes since v2.107:

• Multiple item relative edge mode only works now with items selected, not only grouped.
• Disk read mode now defaults to asynchronous buffered rather than unbuffered.
• Fixed bug where fx UI wouldn't realize they had more channels available before running audio (t=18756).
• Stem rendering now includes project name in stems to avoid overwriting collisions.
• Render dialog: stem rendering now warns on overwrite, shows better filenames.
• Inserting a track now inherits mixer panel sizing from the nearest track.
• Added options to right click menu of item-envelope button in toolbar.
• New option: Add envelope points when moving items
• New option: Add envelope points when ripple editing/inserting time in project.
• Better envelope point adding when add point option is enabled (adds points to edges of nearby items).
• Option to show/hide item labels.
• You can now set the default envelope point shape for new envelopes in prefs/defaults.
• Internal envelope system updates.
• Updated default theme volume envelope colors.
• JS: fixed invalid parameters giving crash.
• ReaXcomp: fixed potential crash when loading presets.
• Updated track/folder mute logic to better use less cpu when tracks are muted (t=16703, 13266, etc.).
• Perf meter: added track names to fx list and fixed "# FX" column.
• Perf meter/fx chains: better zeroing of CPU use when tracks aren't active.
• Perf meter: better auto positioning of everything
• Perf meter: saving of column sizes
• Tweaked media item to item snapping code.
• Tweaked item moving crossfade behavior in free item positioning mode.
• Grouped/selected item edit point editing now edits multiple items (t=17630).
• Removed prefs/playback/"flush media buffers on stop" because it had bad performance implications in many situations.
• Reasamplomatic: fixed bug where sample can have first sample dropped.
• Fixed bug where media items sometimes play 1 sample late.
• Render stems now applies track phase to rendered output.
• Updated media decoders seeking logic, more decoders now support 64-bit file lengths.
• Updated to wavpack 4.41.
• Track/mixer VU meters: internal updates to better support variable sizes.
• Mixer: you can now drag and adjust size of send, fx areas (hold alt to adjust selected, ctrl to adjust all).
• Mac port love.

Mac OS X Preview Build (v0.72)

Changes:

• Bunch of mixer/track panel fixes.
• Theme font fixes.
• Decreased default meter framerate for lower CPU use.
• Basic coreaudio automatic latency compensation for audio hardware (works on my MOTU anyway).
• Fixed included themes/etc.
• Keyboard tweaks for del/backspace support.
• More...

Notes: Requires G4/G5 or Intel Mac, OS X 10.4.x. AU support is still not working yet.