A set of software tools designed to support a rigorous or formal development of software systems using the B-Method. The Toolkit also provides a development environment automating the management of all associated files, ensuring that the entire development, including code and documentation, is always in a consistent state. The Toolkit includes: a specification, design and code configuration management system, including integrity and dependency management and source file editing facilities; a set of software specification and design analysis tools, which includes syntax checkers, type checkers and a specification animator; a set of verification tools, which includes a proof-obligation generator and automatic and interactive provers; a set of coding tools, which includes a translator, linker, rapid prototyping facilities and a reusable specification/code module library; a documentation tool for automatically producing fully cross-referenced and indexed type-set documents from source files; a re-making tool for automatically re-checking and re-generating specifications, designs, code and documentation after modifications to source files. A normal licence costs 25,000 pounds, academic 6,250 pounds.