The Composers Desktop Project (CDP) is an international cooperative network based in the United Kingdom that has been developing software for working with sound materials since 1986. Working on a cooperative basis and motivated by user-specific compositional needs, the project has focused on the development of precise, detailed and multifaceted DSP-based sound transformation tools. Currently, CDP provides sound transformation software (named after the project itself) for Windows and Mac OS X that has been evolving for over 20 years.

In 2014 the main components of the CDP were released as an open-source package licensed under the LGPL. Makefiles are now available for Windows, OSX, and Linux.

Originally, after a study to determine if it was possible and/or feasible to port CMusic from UNIX mainframe systems,^[1] the project released the CDP software along with corresponding SoundSTreamer hardware for the Atari ST^[2] and later ported the software to DOS. The software tool-set is designed specifically to transform sound samples mostly via offline processing (non-real time); the software is considered complementary to real-time processing and audio sequencers.