Within this contribution GENGEDis presented, a development environment for visual languages. GENGEDoffers a hybrid language for defining the syntax of visual languages consisting of an alphabet and a grammar. Correspondingly, the main components of GENGEDare given by an alphabet and a grammar editor. The syntax description is the input of a diagram editor allowing the syntax-directed manipulation of diagrams. The grammar definition as well as the manipulation of diagrams is based on algebraic graph transformation and graphical constraint solving.