Perl is short for 'Practical Extraction and Report Language', and is designed for processing text. Perl has become one of the most popular languages for writing CGI scripts.

PHP Hypertext Preprocessor is a server-side, HTML embedded scripting language used to create dynamic Web pages. PHP includes support for all major operating systems (Windows 95/NT, most versions of Unix, and Macintosh) and web servers (including Apache, Netscape servers, WebSite Pro, and Microsoft Internet Information Server).

MySQL is a true multi-user, multithreaded SQL (Structured Query Language) database server. SQL is the most popular database language in the world.

Although most users will not require these features, it's still nice to know they are available.