they don’t say but I assume this is an implementation of differential dataflow (edit: changed to a better link) [1]
[1] https://www.microsoft.com/en-us/research/wp-content/uploads/...
[1] https://www.microsoft.com/en-us/research/wp-content/uploads/...
There's also the exotic https://dynimize.com/ (unsure of their current state).