Operation War Diary, an ongoing collaborative project between the Imperial War Museum (IWM) and the British National Archives, provides researchers and the general public with richer information about the experiences of WWI soldiers by examining Unit War Diaries from British and Indian Troops. Unit War Diaries were the official journals composed by each unit for the purpose of recording accounts of the war and improving unit practice. The British National Archives has digitized these volumes - over 1.5 million pages, total - and now, in honor of the centenary of the war has collaborated with the IWM. Using the web platform Zooniverse, which is designed to engage the general public in data analysis, Operation War Diary invites "citizen historians" to help tag these diaries through a number of categories, including subject, date, location, weather, and casualties. At this time, the site includes 41 diary pages. Operation War Diary is compatible with PCs using Google Chrome, Firefox, or Internet Explorer 9 or higher and on Mac computers with the latest version of Safari.