Sohu, Sogou and Tencent jointly announced a strategic investment today. Tencent will invest $448 million for 36.5% of Sogou and let the latter merge its own search service Soso. Tencent will allow Sogou’s products, including Sogou Pinyin and Sogou Search, access its huge user base. Sogou developed the most popular Chinese Input Method service Sogou Pinyin. Tencent Soso was launched in 2006 but never gained traction even after former Google China executives joined it.