This is a package of tools in use in Skype for replication and failover. It includes a generic queuing mechanism, PgQ and utility library for Python scripts. The source code was hosted on Pgfoundry (archived) and later on GitHub, tech lead is Marko Kreen. A general overview presentation can be found here: File:Moskva DB Tools.v3.pdf, and a PGQ detailed presentation is at http://www.pgcon.org/2008/