It's actually more specific than that. Take the following Haml that defines a div with an id of "foo" along with a span with class "bar" and content "Hello Wor

It's actually more specific than that. Take the following Haml that defines a div with an id of "foo" along with a span with class "bar" and content "Hello World": #foo %span.bar Hello World If I wanted to hide those elements, I'd write the following jQuery in a separate file: $('#foo').hide(); $('span.bar').hide(); That's really powerful stuff. The Haml syntax for defining elements looks exactly like the CSS3-style selectors used by jQuery, so much so that I often cut and paste my Haml markup into my javascript files.