Analyzing the evolution of large and long-lived software systems is a complex problem that requires extensive tool support due to the amount and complexity of the data that needs to be processed. In this paper we present Churrasco, a tool to support collaborative software evolution analysis through a web interface. After describing the tool and its architecture, we provide a usage scenario of Churrasco on a large open source software system and we present two collaboration experiments performed with respectively 8 and 4 participants. Key words: Software Evolution Analysis, Collaboration, Visualization