Completed 3v4l.org description

README.md

 ## Web Applications
 *Web-based applications and tools.*
 
-* [3V4L](http://3v4l.org/) - An online PHP shell.
+* [3V4L](http://3v4l.org/) - An online PHP & HHVM shell: run code snippets on 150+ versions and analyze them.
 * [DBV](http://dbv.vizuina.com/) - A database version control application.
 * [PHP Queue](https://github.com/CoderKungfu/php-queue) - An application for managing queueing backends.
 * [Composer as a Service](http://composer.borreli.com/) - A tool for downloading Composer packages as a zip file.