Parallaxis is a programming language for data parallel (synchronous parallel) programming. The language is based on sequential Modula-2, which was extended by machine-independent parallel constructs. As a result, Parallaxis can be used on different massively parallel SIMD systems (single instruction, multiple data) - contrary to nearly all commercial languages for SIMD systems. In Parallaxis this abstraction is achieved by a functional declaration of processor arrangements in the network topology. By establishing virtual processors (similar to the concept of virtual memory) and virtual connections parallel application programs can be developed that are independent of the available computer hardware. These application programs are more readable and easier to understand through the declaration of the parallel structure. Parallaxis has been in development at the University of Stuttgart since 1989 and is available as public domain software. It is used worldwide at a large number of universities and research institutions.

The User Manual also contains sample applications, usage of Parallaxis compiler and debugger, as well as an appendix with standard procedures and language syntax.