IJuliaTimeMachine provides two capabilities that I have found useful when running long computational experiments in Jupyter / IJulia notebooks,
It allows you to return variables to a previous state. This is useful if you run experiments in cells that can take minutes or longer to complete, and want to re-examine the variables in a cell you have over-written.
It allows you to spawn a process to run on a thread while you run other cells. The process sandboxes the variables it uses, so it does not impact other cells. This is especially useful if you plan to run many similar experiments: you can copy, paste, and modify them without having to rename the variables inside them.
If others find this useful, I am very open to assistance in adding functionality, increasing stability, and generally improving its behavior.