The SndObj Sound Object Library is a C++ object-oriented audio processing framework and toolkit. This article initially examines some of the currently available sound processing packages, including sound compilers, programming libraries and toolkits. It reviews the processes involved in the use of these systems and their strengths and weaknesses. Some application examples are also provided. In this context, the SndObj library is presented and its components are discussed in detail. The article shows the library as composed of a set of classes that encapsulate all processes involved in synthesis, processing and IO operations. Programming examples are included to show some uses of the system. These, together with library binaries, source code and complete documentation, are included in the downloadable package, available on the Internet. Possible future developments and applications are considered. The library is demonstrated to provide a useful base for research and development of audio processing software.