The paper describes a visual environment generator, the VLPEG system, based on the Symbol Relation Grammar model. The system exploits a classification of visual languages in terms of graphical symbols and the relationships among them. For each class a lexical analyzer is able to interpret the physical layout of any drawn visual sentence and to provide a corresponding high level representation. Thanks to this capability the visual language designer may disregard the physical features and specify the language at a high abstraction level. VLPEG supports the rapid prototyping of visual environments and offers the designer the possibility to operate in automatic generation mode, by exploiting a grammar infere nce module. This capability allows the designer to focus on the structural features of the target language and quickly receive feedback from the customer during the language prototyping process.