DAPPLE is a C++ class library designed to provide the illusion of a data-parallel programming language on conventional hardware and with conventional compilers. DAPPLE defines Vectors and Matrices as basic classes, with all the C operators overloaded to provide for elementwise arithmetic. In addition, DAPPLE provides typical data-parallel operations such as scans, permutations, and reductions. Finally, DAPPLE provides a parallel if-then-else statement to restrict the context of the above operations to subsets of vectors or matrices.