This article provides a historical overview of a decade of the development of the IFAD VDM Toolboxes commonly referred to as VDMTools. All along, the existing tools have been used in the development of new major components. This kind of "bootstrapping " approach where a CASE tool is developed by taking ""its own medicine" is seldom used. However, we believe that this approach is important to be able to better understand what the most important improvements are for the users in practice. This article also describes how the different components have been maintained by a changing development team. We feel that the decisions we have made regarding the parts of the tool which have been formally specified and the parts which have been developed conventionally may provide valuable input for others considering the use of formal specification. The overall organisation of the development environment may also be interesting for other developers.

formal methods, software engineering, VDM, tool support