Rendering Engine Hackability Probe performs a variety of tests to discover what the unknown rendering engine supports. To use it simply extract it to your web server and visit the url in the rendering engine you want to test. The more successful probes you get the more likely the target engine is vulnerable to attack.
For further information, please refer to the whitepaper at https://portswigger.net/research/cracking-the-lens-targeting-https-hidden-attack-surface
You can find a public demo here: https://portswigger-labs.net/hackability/