"In 1914, World War I, the bloodiest war ever at that time in human history, was well under way. However on Christmas Eve, numerous sections of the Western Front called an informal, and unauthorized, truce where the various front-line soldiers of the conflict peacefully met each other in No Man's Land to share a precious pause in the carnage with a fleeting brotherhood. This film dramatizes one such section as the French, Scottish and German sides partake in the unique event, even though they are aware that their superiors will not tolerate its occurrence."Written by Kenneth Chisholm (firstname.lastname@example.org)
The summary above basically says it best. I'd just like to add that Joyeux Noel was nominated for Best Foreign-Language Film at the 2006 Academy Awards. It was more light-hearted and more enjoyable of a movie than the 2001 Bosnia-Herzegovian film No Man's Land, which also dealt with the ridiculousness of war and went on to win the Best Foreign Language Film Oscar. And also unlike NM'sL, Joyeux Noel gives the audience hope in that it shows people who recognize the inanity of war.