Seamless Communication revolutionizes language translation with its family of AI models, enabling natural and authentic communication across languages. The suite includes SeamlessM4T, a massive multilingual multimodal machine translation model supporting around 100 languages, which serves as the foundation for other models like SeamlessExpressive and SeamlessStreaming. These models offer capabilities such as speech-to-speech translation, text-to-speech translation, and automatic speech recognition, with a focus on real-time and expressive translations. The latest version, SeamlessM4T v2, features the novel UnitY2 architecture, enhancing quality and reducing inference latency in speech generation tasks. For developers and researchers, the project provides extensive resources, including pre-trained models, evaluation scripts, and datasets, all available on GitHub. The models are integrated into the fairseq2 library, and additional tools like SONAR and SimulEval support the development and evaluation of translation models. With its commitment to open-source collaboration and state-of-the-art technology, Seamless Communication is at the forefront of breaking language barriers and fostering global connectivity.