Software development projects, in particular open source ones, heavily rely on the use of tools to support, coordinate and promote development activities. Despite their paramount value, they contribute to fragment the project data, thus challenging practitioners and researchers willing to derive insightful analytics about software projects. In this demo we present Perceval, a loyal helper able to perform automatic and incremental data gathering from almost any tool related with contributing to open source development, among others, source code management, issue tracking systems, mailing lists, forums, and social media. Perceval is an industry strong free software tool that has been widely used in Bitergia, a company devoted to offer commercial software analytics of software projects. It hides the technical complexities related to data acquisition and eases the definition of analytics. A video showcasing the main features of Perceval can be found at https://youtu.be/eH1sYF0Hdc8.