Can someone explain what the contextmenu attribute in HTML5 does?

Question

can someone explain what the the contextmenu attribute does and if it can be used with all the HTML elements and can someone point me to some online demos/examples?

Answer 1

You can see how it may look like in this demo: https://bug617528.bugzilla.mozilla.org/attachment.cgi?id=554309

At the time of writing only FireFox 8 supports it.