The framework commonly used for developing machine learning applications is TensorFlow. Developed by Google, TensorFlow provides comprehensive tools, libraries, and community resources that facilitate the construction and training of machine learning models. Its flexibility allows developers to work on a wide range of applications, from simple linear regression to complex neural networks. Additionally, TensorFlow's scalability enables it to handle large datasets efficiently, making it a popular choice among data scientists and researchers for prototyping and production-level machine learning systems.