REAPER may use certain LGPL or other open source licensed components, whose source we provide here:

• SoundTouch (included with REAPER as "soundtouch.dll"): soundtouch.dll source code (includes a modified version of SoundTouch 1.9.0).
• cdrecord.exe source code (based on, with slight modification/bugfix, cdrtools cdrecord.exe)
• FFmpeg source and build files for versions that may be included with REAPER.
• reaper_mp3dec.dll uses mp3dec (which is LGPL licensed), the full LGPL sourcecode is available as part of the REAPER plug-in mini SDK.