The winner of the Rapita Systems prize for the best paper published in 2012 by an early career stage researcher (Research Associate or Research Fellow) in the Department of Computer Science at the University of York was announced today. The judging panel declared Frank Zeyda’s paper entitled "Mechanical reasoning about families of UTP theories" to be the best amongst those nominated, especially with regard to Originality, Significance and Rigour. An honourable mention goes to Ed Powley for his paper on "Monte Carlo Tree Search with macro-actions and heuristic route planning for the Physical Travelling Salesman Problem". Congratulations from everybody at Rapita Systems to Frank, whose efforts have resulted in a cash prize of £200, a certificate, and a trophy that he can keep for twelve months.