TOPCASED stands for Toolkit in OPen source for Critical Applications and SystEm Development. It is a system and software engineering workshop based on Eclipse. It aims to provide the tools required to go from requirements to the implementation stages. Focused on modeling development engineering, it includes several graphical editors (for ECORE, UML, SysML, SAM, AADL, and more), an OCL rules editor and checker, several code generators (SMUC, UML2C, UML2Java, UML2Python), a document generator, gPM (a ticket tracker), xHDL tools, Tramway (a requirements traceability framework), and more. External tools can be easily connected to the workshop through its API or models.