Every other week, Gamasutra examines the fastest-growing Facebook games according to monthly active users, looking at which titles and developers are having the most success attracting new players on the social network. The most popular game on Facebook right now, Zynga's ChefVille, is also the fastest-growing, adding an impressive 8.8 million players for a total of 55.5 million users in just the last week. Late bloomer Zynga Slingo is also growing at a fast clip -- in the last week, it's added 7.9 million players, bringing its total monthly user count to 43.6 million. Its daily active numbers, however, are sinking. Zynga Slingo's sudden popularity is particularly curious because up until two weeks ago, the slot machine and bingo mash-up had only 13.2 million players. That's still much more than most social games, but a third of its current audience. But then in late August, seven months after its initial release, the game experienced a huge burst in popularity. It's not strange to see Zynga titles pick up a bit after their launch, but they almost never see this kind of growth more than half a year after debuting. FarmVille 2 is an example of Zynga's titles taking its time to grow, likely as the company hammers out issues before putting its full promotional muscle beind it. While it's the sequel to one of the social network's biggest titles, FarmVille 2's audience growth is relatively slow, bringing in only 640,000 players last week. The fastest-growing non-Zynga title last week was Kixeye's War Commander, a "mid-core" MMO real-time strategy title. The new game already has 3.9 million users just days after coming out of beta and launching. The full list of the top 20 fastest growing Facebook games along with exact monthly active user counts, are as follows:

Facebook Games Leaderboard

All charts and data are courtesy of Facebook application metrics and trends site AppData.