51 Space is now called 51.com.

51.com is one of the earliest social networks in China, providing dating, space, blogs, photo albums, games and other services. Founded in Shanghai in January 2005 by founder Pang Shengdong, it was once one of the largest SNS websites in China. In 2014, 51.com was acquired by Alibaba Group. Currently, 51.com has become a game-based social platform where users can play various types of games and interact with other players on the platform.