The world wide web basically runs on JavaScript, HTML, and CSS. Unfortunately ... inference allows a few type annotations to make a big difference to the static verification of your code.

jsFiddle is the perfect solution; it provides a custom environment (based on user selections) to test (or fiddle with) your JavaScript, HTML, and CSS code right inside your browser. A quick tour ...

The new release brings improvements to JavaScript heap profiles, CSS code formatting ... the semantic highlighting of JavaScript source in HTML files with what is seen in normal .jscode files.