As part of the program to provide information to Federal agencies on software tools for improving quality and productivity in software development and maintenance, data was collected on software engineering environments. Software engineering environments surround their users with software tools necessary for systematic development and maintenance of software. The purpose of this report is to characterize software engineering environments by type and by their relationship to the software life cycle and by their capabilities, limitations, primary users, and levels of support. This report provides examples of existing software engineering environments that are available commercially or in research laboratories. KEYWORDS framing environments; human factors; life cycle coverage; programming environments; software analysis; software engineering; software engineering environments; software support; software tools. FOREWORD Under the Brooks Act, the National Bureau of Standards Institute for Computer Sciences and Technology (ICST) promotes the cost effective selection, acquisition, and utilization of automatic data processing resources within Federal agencies. ICST efforts include research in computer science and technology, direct technical assistance, and the development of Federal standards for data processing equipment, practices, and software.ICST has published several documents on software tools as part of this responsibility and the growing recognition that the use of software tools and software engineering environments can reduce the effort necessary to develop and maintain computer software. The guidance is designed to assist Federal agencies in automating and standardizing their software development and maintenance projects. This report presents the results of the analysis of data and experience accumulated on software engineering environments. It characterizes environments and describes their features to enable readers to gain an understanding of how environments can aid software development and maintenance process. Future ICST documents will provide guidance in selecting and using software engineering environments.Certain commercial products are identified in this paper for clarification of specific concepts. In no case does such identification imply recommendation or endorsement by the National Bureau of Standards, nor does it imply that the material identified is necessarily the best for the purpose.