This PhD submission comprises two parts: firstly, a portfolio of original compositions (80%) and secondly, a critical overview of the Composers' Desktop Project (20%). The compositional portfolio contains both acoustic and electronic elements. The former includes works for different groups ranging from a solo instrument, to vocal ensemble and symphonic band. The electronic works include the use and manipulation of pre-recorded and synthesised sounds. Electronic elements are sometimes employed solely or in conjunction with acoustic instruments. The approach to composition is multi-faceted, a pluralistic multi-disciplinary approach. It draws on a variety of techniques to turn abstract ideas into music. This exploration and extension of compositional techniques is the main target of this research. The Composers' Desktop Project is a set of time and frequency domain sound transformation tools, working offline, developed by a cooperative group of electroacoustic composers, sound designers and programmers since 1987, based in the DK. This research project is a study to review the current state of CDP and to assess its ongoing usefulness. As a result of this research, I hope to raise awareness of this software and encourage future development.