In Forrester's first 19-criteria evaluation of activities streams vendors, Forrester identified the five significant players — Neudesic Pulse, Salesforce Chatter, Socialcast by VMware (Socialcast), Tibco tibbr, and Yammer — and researched, analyzed, and scored them. This report details our findings about how each vendor measures up, and it plots where they stand in relation to each other. This report and associated Excel model highlight the key criteria IT leaders should evaluate when considering activities streams as part of a broader social technology strategy.