JavaScript (back-in-time) debugger

Part of the Lively tool suite is a framework to control program execution. The framework allows to to implement a JavaScript debugger directly inside the browser without the need for browser extensions or VM debugging APIs. Apart from convenience this allows to implement features such as back-in-time debugging and edit-while-debugging that cannot be found in most debuggers.

This evolved as joint work with Marko Röder and Christopher Schuster. The framework itself is presented here.