APC, which stands for Alternative PHP Cache, is a framework used for caching the compiled source code of a script application, that could boost a database-driven Internet site several times. Every time a PHP page is accessed, the script pulls the website content that has to be shown from a database, parses and compiles the code, then the result is displayed to the site visitor. While this is necessary for websites with routinely changing content, it is a waste of processing time and resources for a site which does not change, for instance an informational portal that shows the same content on a regular basis. As soon as the pages for such a site are compiled, APC caches them and delivers them any time a website visitor loads them. Since this saves the time to get content from the database and to parse and compile the program code, the Internet site will load much quicker. APC is really effective in particular for scripts with massive source code.