Disclaimer: this is not an official Google product
An implementation of John Tromp's lambda diagrams graphical notation for lambda terms. It reads a lambda term on the standard input and renders an animation of its evaluation.
This youtube playlist showcases animations produced with this program.
Usage:
stack build
stack exec lambda-diagrams < prog.lam
avconv -framerate 10 -f image2 -i /tmp/out_%04d.png -c:v h264 -crf 1 lam.mp4