The RPP file format is a proprietary project file format used by REAPER (Rapid Environment for Audio Production, Engineering, and Recording), a professional digital audio workstation (DAW) developed by Cockos. Unlike many other DAW project files that store audio data within the project file itself, an RPP file is essentially a text-based script that contains all the metadata, routing information, track settings, plugin configurations, automation envelopes, and edit decisions for a specific session. Because it is stored in a human-readable text format, it is highly efficient and lightweight, allowing users to open and edit the project structure in a standard text editor if necessary. The file does not contain the actual audio samples; instead, it maintains references to the external audio files stored on the user's hard drive. This architecture makes RPP files extremely portable and easy to back up, as the project file size remains small regardless of the complexity of the audio session. It is the core format for professional music production, sound design, and post-production workflows within the REAPER ecosystem.