Dan North has developed a number of frameworks that support BDD (including JBehave and RBehave), whose operation is based on the template that he suggested for recording user stories. These tools use a textual description for use cases and several other tools (such as CBehave) have followed suit. However, this format is not required and so there are other tools that use other formats as well. For example, Fitnesse (which is built around decision tables), has also been used to roll out BDD.