Chalktalk is an interactive, performative presentation tool that allows for improvisation and limitless extensibility. The features of a chalkboard are combined with tools for drawing sketches that can come to life and turn into animations, simulations, interactive components and 3D animated objects and scenes. Live sketches can be connected to one another using a node based visual programming environment which includes the ability to edit code interactively, create motion paths, interact with physics based procedural animation, create complex relationships between elements, etc. The result is a tool for presentation that avoids visible user interface components and allows compelling presentations that can be reordered and linked arbitrarily during the presentation itself. The delivery of topics in a lecture is enhanced by the narrative quality of drawing, and these drawings then provide depth via their interactivity. The fact that the lecture is supported by an integrated combination of drawing and active simulation engages audiences visually, aurally, emotionally and kinesthetically.