The design of programming environments implies the integration of different tools in order to provide the user with an uniform framework. Tools integration may be envisaged from different points of view: from a merely visual integration among non-cooperative tools, to a complete data and control integration. This paper is intended to present the work done on designing an architecture suitable to serve as a framework for distributed programming environments, together with a user interface generator able to provide a visual integration level to UNIX-like toolsets. This architecture is based on the use of a syntactic server able to manage partial attributed abstract syntax trees, and an environment controller in order to ensure the consistency among partial AST's.