Software measurement (SM) is a key area to support process quality improvement and project management. Due to the nature of the measurement activities, tool support is essential. Tools can be combined to support the SM process and provide necessary information for decision making. However, tools are usually developed without concern for integration. As a result, organizations have to deal with integration issues to enable communication between tools. Aiming at investigating studies in the literature that report initiatives involving tool integration for supporting SM, we performed a systematic literature review. Twelve initiatives were found. This paper presents the results of the systematic review and discusses the main findings.