RepOSS is an OSS (Open Source Software) assessment repository. In the ICT (Information and Communication Technology) field, OSS has important roles as key components of systems these days. There are many OSS projects, and these numbers are increasing every day. As of March, 2012, more than 320 thousand OSS projects and about 3.4 million OSS developers have been registered into SourceForge.net®.In order to choose which OSS is more suitable for your use, OSS information based on criteria will be useful as references. Compared to adoptions of proprietary software with an agreement like an SLA (Service Level Agreement), you may be concerned about the Quality of OSS, Continuity of OSS communities, OSS License restrictions, and so on. To promote OSS adoptions and applications with respect to concerns, such as these, RepOSS provides practical OSS references and assessments. RepOSS prepares more than 100 assessment properties of the OSS project. RepOSS is used as a workbench of OSS assessments by using information in its repository. RepOSS is providing Objective and Quantitative information, which is able to be gathered publicly. You are able to assess OSS by your own assessment method with the RepOSS information and your own queries.RepOSS currently contains information for about 300 OSS projects. In light of the explosively increasing number of OSS projects, we publish RepOSS as an OSS community development methodology. We will continue to work under this methodology to enrich the contents of RepOSS. Therefore, we would appreciate it if you could join the RepOSS project for enriching OSS information with us.