Website != API. A cleverly-written API can exist in the same space as a Website (even the same URLs, if you differentiate by things like Accept: headers), but t

Website != API. A cleverly-written API can exist in the same space as a Website (even the same URLs, if you differentiate by things like Accept: headers), but they're not the same thing. It's perfectly acceptable for Websites to include, and even require the use of, JavaScript. It's also perfectly acceptable to offer a JavaScript client for your API. In fact, you pretty much have to do that if you want your Website to work with the API anyway. What's not OK is for an API to require downloading and using additional JavaScript while the API is being used. As a contrived (and somewhat ludicrous) example, let's say that I queried "http://foo.com/bars" http://foo.com/bars" for some kind of collection. It's OK to return the collection. It's even OK to use an HTTP redirect if the collection actually resides elsewhere: HTTP 302, perhaps, with a Location of "http://foo.com.bazes" http://foo.com.bazes". What's not OK is to return a line of JavaScript reading "window.location = 'http://foo.com/bazes';" http://foo.com/bazes';" which might work for the browser, but wouldn't work for most other clients.