"]po[ is an enterprise project management tool with many features, including support for Agile. The software is released under a mixed source model, or a "dual license", meaning that at it’s core it is open source, with additional modules released under a commercial license. ]po[ runs as client software on both Windows and Linux, depending on a stack of open source packages."
According opensource.com, it was among the top 5 open source project management tools in 2014. Frank Bergmann, founder of ]po[, says that about 6,000 companies worldwide use ]po[.