Frameworks are used to enhance the quality of applications and the productivity of the development process, since applications may be designed and implemented by reusing framework classes. However, frameworks are hard to develop, learn and reuse, due to their adaptive nature. From Feature to Frameworks (F3) is an approach that supports framework development in two steps: Domain Modeling, to model domain features of the framework; and Framework Construction, to develop framework source-code based on the modeled domain and on patterns provided by this approach. In this article, it is presented the From Features to Framework Tool (F3T), which supports the use of the F3 approach on framework development. This tool provides an editor for domain modeling and generates framework source-code according to the patterns of the F3 approach. In addition, F3T also generates a Domain-Specific Modeling Language that allows the modeling of applications and the generation of their source-code. F3T has been evaluated in two experiments and the results are presented in this article. F3T facilitates framework development and reuse by omitting implementation complexities and performing code generation.