In this paper, we describe the architecture and the functionality of our own OCL tool called RoclET. Besides standard features of OCL tools such as editing of class and object diagrams and parsing of OCL assertions (invariants, pre-/post-conditions), our tool supports also the evaluation of OCL constraints in a given system snapshot (object diagram), refactoring of UML/OCL models, and impact analysis. RoclET is deployed in form of an Eclipse plugin.