Visual programming languages strive to simplify the intricate process of programming by capitalizing on innate human perceptual skills. However, visual representations of general-purpose programming constructs provide little support to end-users in creating programs in specific problem domains. To empower end-users, visual languages need to be tailored toward the domains in which they will be used. End users must collaborate with language designers to create and maintain effective, domain-oriented visual programming languages. Agentsheets is a system that (1) supports visual language designers in developing domain-oriented languages consisting of constructs that are pertinent to end users, (2) stimulates an iterative design approach by facilitating the incremental modification of the look and behavior of domain-oriented languages, and (3) provides role-specific views containing specialized tools that support collaboration between end users and language designers.