What is #! doing before all my routes in Meteor? (Using iron-router)

Question

My routes have started appearing in the form: http://localhost:3000/#!team/Wdv9zGinoMbp5a7cj

The addition of the #! must be quite new. What is it? And why was it added? Did a package that I added cause this? Or was it an Iron Router update that did it?

Answer 1

This is generally due to the appcache package. See this discussion.