Many developers have used the online CSS Lint tool to check their CSS code. Now the owners of CSS Lint have made the tool open source, opening it up for additional third party development and use.
CSS Lint carries a tagline that says, “Will hurt your feelinngs (And help you code better)”. To use the service, simply visit the CSS Lint website and enter your CSS into the form field. CSS Lint does the rest, pointing out errors and warnings for your CSS code, with suggestions on how to improve it.