The Gesture Recognition Toolkit (GRT) is an open-source, cross-platform toolkit designed for real-time gesture recognition and machine learning applications. It is developed by Nick Gillian and is accessible on GitHub at https://github.com/nickgillian/grt. The GRT facilitates the development and implementation of gesture recognition systems by providing a range of algorithms and tools. It supports classification, regression, clustering, and more, making it suitable for a variety of interactive applications. The toolkit is written in C++ and emphasizes ease of use, modularity, and flexibility, enabling developers and researchers to implement and experiment with gesture recognition and machine learning techniques efficiently.