
The Microsoft Cognitive Toolkit (CNTK) is an open-source toolkit for deep learning, offering commercial-grade capabilities. It uses neural networks represented as computational steps via a directed graph, supporting popular models like DNNs, CNNs, and RNNs, with functionalities such as stochastic gradient descent and automatic differentiation. CNTK supports both 64-bit Linux and Windows, and it is compatible with several programming languages including Python, C#, and Java. It also supports the Open Neural Network Exchange (ONNX) format, facilitating model sharing across different frameworks.