Jubatus is an open-source online machine learning platform designed for big data analytics, allowing for real-time and deep analysis without the need for storage or data sharing. It offers unique features like online learning and a loose model-sharing system, differentiating it from existing frameworks like Hadoop and Mahout. The platform supports various machine learning functions, including classification and anomaly detection, and has demonstrated high efficiency in applications such as Twitter data classification and real-time power consumption estimation.