Yep, you can see swagger and swagger-ui keywords all through the source of that docs page.

In fact, they're still using Swagger 1.0[0] from 2011 which wasn't even formally specified, and currently-available copies of the spec[1] had to be unearthed from the wayback machine.

[0] https://gateway.marvel.com/docs/public [1] https://github.com/Mermade/swagger1/blob/master/versions/1.0...

Devs: SOAP is too baroque

Swagger: hold my beer