Abstract. We propose a new implementation scheme for XML transformation languages through derivation of stream processors. Most of XML transforma-tion languages are implemented as tree manipulation, where input XML trees are completely stored in memory. It leads to inefficient memory usage in particu-lar when we apply a facile transformation to large-sized inputs. In contrast, XML stream processing can minimize memory usage and execution time since it begins to output the transformation result before reading the whole input. However, it is much harder to program XML stream processors than to specify tree manipula-tions because stream processing frequently requires ‘stateful programming’. This paper proposes an implementation scheme for XML ...