While I am at it, did not see it coming, but towards the end the twist is that Joker is the bad guy.
Once you know and rewatch it you see all these subtle clues along the way.
Careful now. That kind of provocative black-and-white claim will only alienate the 50.1% of American voters who appreciate Mr Joker’s anti-government and anti-woke agenda.
my guess would be batman.js
The CoffeeScript rails clone? Seems an unlikely inspiration for this
I think it means actual Batman. The web dev who uses this framework is encouraged to roleplay Batman.