Less is a CSS pre-processor: it extends  CSS by adding variables, mixins, functions and many other techniques that allow easier maintenance of your browser stylesheets.

You can compile Less either on the client side, or on the server.  We thought it didn’t matter; but it turns out that Google search engine crawler doesn’t like the client-side compilation:

If you are using Less on your website, you might want to also avoid client-side compilation so that Google doesn’t barf on it…