Company of Heroes: Opposing Fronts is the stand alone expansion pack to Company of Heroes, a real-time strategy game for computers running the Windows operating system. It was announced on April 5, 2007. Opposing Fronts was developed by Canadian-based RTS developer Relic Entertainment, and published by THQ. The game was released on September 25, 2007 in the US and September 28 in Europe. Another standalone expansion to the CoH series, Tales of Valor, was released in April 2009.GameplayDynamic Environmental Effects SystemOpposing Fronts implements a Dynamic Weather Effects system consisting of real time weather effects and day-to-night time transitions. In addition to these enhancements, particular birds sing at various times of the day and during specific weather patterns. Although Relic had initially indicated otherwise, the Dynamic Weather Effects system has no tactical impact on the battlefield.New Single-Player CampaignsOpposing Fronts introduces two new single player campaigns. The campaigns feature gameplay from the British perspective and the German perspective. The British campaign is based on the Liberation of Caen. It features nine missions focusing on the attack by British and Canadian forces from Sword, Gold, and Juno Beaches to the city of Caen. The German Panzer Elite's campaign is based on driving back Allied forces during Operation Market Garden. It features eight playable missions following a Panzer Elite Kampfgruppe in occupied Netherlands that is bracing itself for one of the largest airborne invasions in history.