Last summer, Uber and Didi Chuxing struck a truce, with Uber selling its ridesharing business to Didi in exchange for about a 20% stake in the combined company. That peace deal didn't last long. On Wednesday, Didi announced it has made a "strategic investment" in 99 (formerly 99Taxis), an Uber competitor in Brazil and self-proclaimed market leader in Sao Paulo and Rio de Janeiro. Didi will provide guidance and support for 99, including in "technology, product development, operations and business planning." Didi said specifically that it will share "data-driven algorithmic capabilities" too.