UCCL

Yang Zhou, Zhongjie Chen, Ziming Mao, ChonLam Lao, Shuo Yang, Pravein Govindan Kannan, Jiaqi Gao, Yilong Zhao, Yongji Wu, Kaichao You, Fengyuan Ren, Zhiying Xu, Costin Raiciu, Ion Stoica | Apr 24, 2025

UCCL is an extensible software transport layer designed for modern GPU networking workloads such as collective communication, KV-cache transfer, and RL weight transfer. It demonstrates substantial gains over NCCL on cloud GPUs and accelerates distributed training and LLM serving.