In assembling a CASE environment from a collection of commercial off-theshelf (COTS) tools, tool users must find ways to connect the tools such that they provide adequate support for their particular software development approach. This task takes place in the context of limited knowledge of the tools, limited access to the source or internal structures of the tools, limited resources with which to perform and maintain the tool connections, and evolving understanding of the needs of the tool users. This places severe restrictions on what can be attempted in terms of tool interconnection. Environment framework technologies (e.g., ECMA PCTE, ATIS, BMS, ToolTalk, or CORBA) claim to provide a set of common integration services that aid in the tool integration process. There have been numerous discussions about the value, maturity, and complexity of these framework technologies. Such discussions are characterized by three points: general agreement that framework technology per se is a valuable goal to pursue; moderate disagreement as to whether the current level of framework technology is a sufficient basis for production quality CASE environments; and considerable disagreement about which of the current technologies are the most likely to mature and succeed. Notable about these discussions, however, is that there has not been extensive use of the technologies in question. This stems from several sources: their expense, their unfamiliarity and complexity to current tool users, and a widespread concern about their immaturity. This lack of use is perhaps understandable, but it has had the additional effect that partisans of one or another technology have made assertions based on little factual information about the relative merits of the technology in question. To expand our own expertise in tool integration and framework technologies, and to answer the question, “What tool integrations are possible for third-party tool users given the current state of COTS tools and integration technology?” we performed a set of experiments involving the integration of a collection of common COTS tools with environment framework technologies in support of a typical development scenario. Our selection of these tools and technologies was based on common availability and application to the development scenario(s) of interest.