Dunno, I have/had no problems on Win x64 since REAPER 3.xx up to the latest (beta) version...

 

REAPER 5.1 coming soon. Huge update since 5.04.
First Release Candidate. Final version is on the horizon)

v5.1rc1 - November 10 2015
+ MIDI: fix relative editing of 14-bit CC pairs
+ MIDI: support CC multiplies/divides by non-whole values [t=168580]
# Freeze: use -139dB for silence detection rather than -200dB

 

REAPER 5.1 Officially Released!

v5.1 - November 15 2015
+ API: add GetTakeStretchMarkerSlope, SetTakeStretchMarkerSlope
+ API: fix TrackFX_SetPreset() return value
+ API: support spaces in section names for SetProjExtState()
+ Actions: add apply track FX to items as new take (multichannel)
+ Actions: add toggles for ripple per-track and all tracks
+ Actions window: use logical description sorting
+ Actions window: allow executing single visible action without first selecting
+ Actions window: enable enter in filter window to run action on Windows
+ Actions window: allow configuration of closing after run for doubleclick/enter, for docked and undocked states
+ Actions window: prevent truncated custom action names in the editor [t=166802]
+ Batch converter: support writing markers/regions
+ Cues: support cues/regions for reversed takes, section takes
+ Cursors: added arrange_stretchmarker and arrange_stretchmarker_rate
+ Directory cleanup: improve support for very long filenames and UTF-8
+ Editing: fix replace media item source via drag and drop [p=1594810]
+ Explode multichannel audio: handle start offsets, stretch markers, and looping items correctly
+ FX browser: allow inserting single visible FX without first selecting
+ FX browser: fix recent filter list when clear filter on close set
+ FX browser: allow switching from filter to list via enter, arrow keys
+ Freeze: automatically remove silent media from disk
+ Freeze: fix silence detection (which was inadvertently disabled in 4.16)
+ Freeze: improve render region detection for complex routing [t=168221]
+ Freeze: better handle unfreezing duplicated frozen items [t=165138]
+ Glue: add preference to loop glued items [t=167870]
+ Glue: improve glued item filename generation, make item labels consistent with files
+ Audio/midi devices: improve device error notification window, preferences to disable
+ JSFX: improve mouse behavior with touch screens or multiple mouse buttons pressed
+ JSFX: improve parameter text editing behavior (enter to commit)
+ JSFX: add export_buffer_to_project()
+ JSFX: add new 8-channel MIDI-controlled synchronized audio looper, Super8
+ JSFX: support __memtop() builtin function to query script memory size
+ JSFX: support options: maxmem=xyz up to about 32 million items
+ Keyboard: support F12-F24 keys
+ Localization: fix various localization issues, make new template LangPack available
+ MIDI: fix event corruption when handling MIDI with mixed note-on/note-off messages for the same note at the same time
+ MIDI: add option to disable pitch/CC reset on looped playback
+ MIDI: add options in Preferences/Playback to reset CC/pitch on playback start, stop
+ MIDI: make all-notes-off/pitch reset options in preferences/MIDI Devices only affect MIDI hardware devices
+ MIDI: add options for hardware reset for play/stopped modes
+ MIDI: fix relative editing of 14-bit CC pairs in editor
+ MIDI: ignore MIDI message receive after close of some buggy win32 MIDI input devices
+ MIDI: improve win32 output device shutdown sequence, notify user when a device has hung
+ MIDI: do not reset pitch at end of items
+ MIDI: chase to pitch of previous items
+ MIDI: option to disable MIDI note-on chasing
+ MIDI: remove option to reset CC on playback start
+ MIDI: send only necessary note-offs when a track is un-record-armed or un-monitored
+ MIDI: support CC multiplies/divides by non-whole values [t=168580]
+ MP3: display ID3 tags in source properties
+ Media Explorer: improve support for .LNK files, hidden/system folders on Windows
+ Media Explorer: allow configuration of column order and visibility
+ Media Explorer: improve UTF-8 support on Windows [issueid=5271] [issueid=5062]
+ Media Explorer: improve playback/preview behavior in various configurations
+ Media Explorer: increase shortcut list customization
+ Media Explorer: use a better layout when small width set
+ Media Explorer: support metadata in databases (ID3 tags, RIFF LIST-INFO, BWF descriptions)
+ Media Explorer: search improvements
+ Media item properties: do not reset take start offset when enabling section with specified position
+ OSX: improve drawing quality on on 10.10+
+ OSX: fix action support for F17-F19, NumPad enter
+ OSX: workaround various 10.11 issues
+ Parameter modulation: add option for free-running LFO (does not reset on seek/loop)
+ Performance: improve project/undo state loading performance
+ Project bay: use logical sorting
+ ReaScript: improve gfx mouse behavior with touch screens or multiple mouse buttons pressed
+ ReaScript: support __memtop() builtin function in EEL to query script memory size
+ ReaScript: use deterministic command ID string when adding scripts as actions
+ ReaVerb: fix prompt for test tone when deconvolving on OSX [t=74360]
+ Render: when rendering selected media items with tails, prevent rendering the start of the following media item
+ Search: do not treat back-tick as a quoting character, handle unterminated quotes
+ Search: support ^foo, foo$, and "foo" for matching start/end/words
+ Stretch markers: support for linear rate transitions between markers
+ Stretch markers: add action to manually edit stretch rates
+ Stretch markers: add mouse modifier context for marker rate, various rate-envelope-like behaviors
+ Stretch markers: add mouse modifier context for stretch marker double click
+ Stretch markers: adjust media item length automatically when editing stretch markers
+ Stretch markers: fix quality issues with 0ms stretch marker fade
+ Virtual keyboard: improve behavior when switching channels, octaves while notes are being played
+ VST: improve VST3 sysex handling
+ VST: prevent reset/delay on playback with Vienna Ensemble Pro VST2 [iid=5532]
+ VST: add option to not send notes-off or pitch-reset messages on stop/reset
+ VST: improve VST3 UI threading issues
+ WAVE: display RIFF LIST-INFO metadata in source properties
+ Windows: use current locale for date formatting
+ Windows: support drag and drop of file URLs

 

Last edited: Dec 25, 2015

5.11 in process

v5.11pre2 - November 17 2015
+ Render: transform rendered cues by project playrate
# ReaProxy: do not add proxied projects to recent list
# ReaProxy: fixed online/offline bug
# ReaProxy: prevent control surface refreshes when loading/rendering

v5.11pre1 - November 17 2015
+ Cues: allow encode of literal =START/=END into files using \=START and \=END
+ FX browser: fixed video processor/ReWire default preset issues
+ Glue: better support take FX on multichannel tracks
+ Glue: generate audio when a MIDI item has take FX that can produce audio
+ ReaProxy: support embedding projects within projects
+ Render item as new take: improve take FX support (multichannel, MIDI-to-audio)
+ Render/Windows: fix $user and $computer wilcards with international characters
+ Render: allow control of full-project render region with markers named =START and =END
+ Render: options to include tails when rendering time selection, regions, etc
+ Render: use stereo/multichannel stem rendering when encountering take FX on mono items
+ VST3: make compliant plug-ins adapt their channel count to the track channel count
# Render: fixed certain instances where audio device would not be reopened following render
# Updated to libpng 1.6.19

 

v5.11pre3 - November 19 2015
+ Media explorer: adjust minimum docked width based on customized left pane size
+ VST3: improve resize behavior
+ VST: improve OSX Cocoa UI resizing behavior
+ VST: improve bridged plug-in UI drawing behavior on Windows
+ VST: improve plug-in UI drawing behavior on Windows
# Envelopes: fix envelope edit dialog issues with some plug-ins [p=1597682]
# Media Explorer: fix track template context menu
# Render: fix $item wildcard when rendering without tails [p=1597786]

 

v5.11pre4 - November 22 2015
+ MIDI editor: add actions to set grid type (straight, dotted, triplet, swing)
+ Parameter modulation: allow controlling/modulating FX parameters with track MIDI events/monitoring
+ ReaControlMIDI: fixed slider feedback for incoming channel pressure messages [t=168996]
+ Recording: enable auto-new file switching for background recording projects
+ Recording: fix filename format not always being used when recording [p=1599369]
+ Render: optionally embed tempo for rendered items that have constant tempo, even if the project contains tempo changes [p=1598553]
+ Windows: improve various display issues on Japanese editions of Windows
# Clean project directory: better handling of ReaProxy projects
# VST: fix small OSX resize glitch

 

getting better to be the best

v5.11pre5 - November 28 2015
+ MIDI editor: add CC/mousewheel action to adjust swing grid strength
+ Main window: increase default track panel width on new installs
+ Multiprocessor: support up to 64 worker threads (up from 32)
+ Recording: disable default fades when gaplessly switching recorded files
# ReaProxy: apply parent tempo/configuration to inserted projects when loading from template
# ReaProxy: option to synchronize any parent projects when playing back reaproxy
# ReaProxy: use project render realtime/online setting for proxy renders
# Recording: avoid adding extra empty takes when gaplessly switching files
# Recording: improve spare sink creation to avoid unnecessary temporary files

 

v5.11pre6 - December 1 2015
+ FX Browser: add option to clear folder view on close
+ FX browser: properly restore view state when viewing VST folders
+ FX browser: scroll selected tree item into view when restoring view state
+ Render: fix potential crash when rendering items
# ReaControlMIDI: fixed incorrect parameter feedback [p=1602604]
# Render: faster rendered cues project playrate transformation

 

v5.11pre7 - December 2 2015
+ FX add: keep current tree item visible when sizing
+ FX browser: improve keyboard behavior in search field, add select all key
+ VST: possibly fix display issues with some bridged, embedded plug-in UIs on Windows
# ReaProxy: potentially fix some control surface issues
# Toolbars: Actions to set grid division report their state

 

v5.11pre8 - December 5 2015
+ Crop project: fix behavior when cropping during a linear tempo change
+ FX browser: faster initial load after reboot
+ MIDI editor: add actions to set grid division preserving grid type [p=1603546]
+ ReaProxy: add move items to ReaProxy subproject action, non-destructive glue
+ ReaProxy: use time selection when inserting new reaproxies
+ SMPTE/Click source: use time selection when inserting
# FX browser: send most keyboard input to the filter box when focused
# MIDI editor: name grid-setting actions more descriptively

 

Seems to be the only DAW that will be polished as diamond.

v5.11pre9 - December 9 2015
+ FX: put effects in a temporary offline mode when loading projects in recovery mode, do not require manual online of all plug-ins before saving
+ Project save: improve handling of frozen take FX with copy/trim
+ ReaProxy: add action to move tracks to subproject
+ ReaProxy: add option to defer rendering of reaproxies until tab switch (rather than on every save)
+ Render item as new take: added new 'Render items to new take' action which improves handling of take FX channels/MIDI-ness
+ Render item as new take: renamed previous 'Render items to new take' to 'Render items to new take (preserve source type)'
+ Stretch markers: fix peak display inaccuracies
+ Video: fix potential crash when encoding .gif from RGB sources
# FX browser: tweak resize treeview scroll behavior
# ReaProxy: copy time selection and cursor position to new project
# ReaProxy: do not load project template when moving items to subproject

 

I know about his previous work - Winamp.
The latest Winamp version is 5.666 (Build ...), now it has been sold to another company. Nobody knows the future of Winamp...
But REAPER seems to be the DAW of the future...Who knows what will be next...Imagine REAPER 6 or 7...or higher..wooooow

 

Yes !!! With Score view/edit of multiple midi tracks. Better /easier midi routing for arpegiators and a whole bunch of things more ...

 

Notation Editor will be soon...Possibly it is testing now...because they introduced it in 5.00pre-betas and days later it was removed because "it is early days, it'll be back later"...a lot of bugs and errors...maybe REAPER 5.5 will have it..who knows

 

preten

v5.11pre10 - December 10 2015
+ Project tabs: obey synchronized tab playback option when starting recording
+ Stretch markers: improve behavior of 'Loop section of audio item source' with stretch markers
# Render items as new take: fixed channel counts
# Stretch markers: improve peak/sample display with differing rates

 

eleven 4 five-eleven

v5.11pre11 - December 11 2015
+ Audio Units: Cocoa UI fixes
+ Audio Units: improve generic UI scroll-resize behavior
+ OSX: disable scroll bars when hosting VST/AU GUIs
+ OSX: improve support for Waves plug-ins
+ Project tabs: only send MIDI clock for active project
+ Stretch markers: improve behavior of linear transitions when reversing takes
+ Take reverse: better handling of non-looped take start offsets
+ VST: improve generic UI scroll-resize behavior
# Project tabs: synchronize count-in/pre-roll on playback start

 

v5.11pre12 - December 14 2015
+ Batch converter: fix support for Audio Units
+ Batch converter: improve support for MIDI in chains, MIDI to audio conversion
+ MIDI editor: fix previews when stopped and 'run FX when stopped' is disabled [p=1607366]
+ Playback: improve accuracy when stopping at end of loop selection
+ Region manager: fix stop playback at end of region
+ Stretch markers: stretch markers affect item media cue/regions

 

v5.11pre13 - December 15 2015
+ API: FX preset related functions support VST3 preset files
+ API: make TrackFX_SetPresetByIndex support factory and default user presets
+ Media Explorer: add context menu item to remove selected files from database
+ Media Explorer: add custom/editable database tag
+ Media Explorer: apply tempo match and pitch settings when dragging mutltiple files to the Project Bay
+ Media Explorer: apply tempo match and pitch settings when dragging mutltiple files to the arrange view
+ Media Explorer: drag-drop directories to database shortcuts (to add/scan paths)
+ Media Explorer: drag-drop files to database shortcuts (to add files)
+ Media Explorer: make drag-drop to the arrange view obey the option 'Enable looping when inserting selected portion of media'
+ Media Explorer: make drag-drop to the project bay obey the option 'Enable looping when inserting selected portion of media'
+ Media Explorer: make render-drag-drop to the arrange view preserve pitch settings
+ ReaSynth: make old style tuning optional, off by default, on in legacy presets
+ VST3: 'Link to MIDI program change' support .vstpreset files
+ VST3: fix some user preset switches
+ VST3: prevent confusions about the currently selected .vstpreset file