This paper describes the Open P2P tracing system which aims to improve the research community?s understanding of P2P file sharing systems by providing continuous and up-to-date traffic data which is anonymized and made freely accessible to all interested parties. It is our hope that this open data set will grow over time into a resource capable of exposing trends in P2P network usage and promote research into the socio-technical factors that drive user behaviour on P2P file sharing systems.