Ripple's key competitor, at least in the crypto sphere, is widely considered to be Stellar. Stellar offers a distributed payments network to provide fast and affordable cross-border transactions. It too relies on its own native currency, Stellar Lumens (XLM).
Stellar was actually created by Ripple co-founder Jed McCaleb. There are plenty of similarities between the projects but some key differences as well. Perhaps the biggest difference is a philosophical one. While Ripple is focusing on banks and the corporate end of town, Stellar's goal is to provide low-cost financial services to people in the world's developing countries. The project's ambition is to facilitate direct peer-to-peer transfers rather than transfers via companies or banks.