This paper introduces MT, a collection of integrated tools for specifying and analyzing real-time systems using the Modechart language. The toolset includes facilities for creating and editing Modechart specifications. Users may symbolically execute the specifications with an automatic simulation tool to make sure that the specified behavior is what was intended. They may also invoke a verifier that uses model-checking to determine whether the specifications imply (satisfy) any of a broad class of safety assertions. To illustrate the toolset's capabilities as well as several issues that arise when formal methods are applied to real-world systems, the paper includes specifications and analysis procedures for a software component taken from an actual Naval real-time system.>