TAMPR (Transformation Assisted Multiple Program Realisation System) is one of the earliest TransformationSystems around. TAMPR supports program transformation by means of rewrite rules. A set of rewrite rules is used to transform the abstract syntax tree of a program to canonical form by exhaustive application. A number of such canonicalizations can be combined by sequential composition. This sequential composition provides a simple mechanism for control over the application of rules. The system has been applied to the derivation of a number of numerical software packages, including LINPACK.