This document summarizes Osmose-QA, an open-source tool for quality assurance of OpenStreetMap data. It uses analyzers running on the OSM database to detect issues. It can also integrate external open data sources like OpenData and Mapillary to identify discrepancies between OSM and other datasets. MapCSS is supported for writing validation rules, with the rules compiled and run by Osmose-QA. A common validation language and shared rule repository are proposed to improve collaboration.