htmlab

The Interactive HTMLab is a tool for demonstrating and experimenting with HTML markup. It runs within a web browser, using JavaScript and CGI. HTML documents may be created or marked up on-the-fly, and the results immediately displayed or validated.

The Interactive HTMLab is implemented by the htmlab.cgi CGI script. This script requires perl version 5 and the LWP::UserAgent module.

Do not even consider retrieving this unless you are reasonably competent with perl. All you are getting is a bare script with no documentation. You will almost certainly need to tailor it to work in your environment. For instance, the do-validate.sh script (launched by the VALIDATE button) almost certainly won't run as-is in your environment.