The VSIPL++ library uses a variety of C++ namespaces. Features that are part of the VSIPL++ standard are in the vsip namespace, while features that are CodeSourcery extensions to the standard are in the vsip_csl namespace. Both of these contain impl sub-namespaces, which hold implementation-specific features and functions.

The vsip_csl namespace also contains sub-namespaces for specific sets of features. The vsip_csl::img namespace contains features for image processing; the vsip_csl::output namespace contains features for data output, and the vsip_csl::stencil namespace contains features for stencil operators.