Core requirements

Elgg runs on a combination of the Apache web server, MySQL database system and the PHP interpreted scripting language. This is the most popular web server environment in the world.

Due to Elgg's advanced functionality, there are some extra configuration requirements:

• The Apache web server needs to be installed with the following modules:
  • mod_rewrite
  • PHP 5
• MySQL 5+ is needed for data storage
• PHP 5.2+ needs to be installed as an Apache module (not in CGI mode or safe mode) with the following libraries:
  • GD (for graphics processing, eg user icon rescaling and Captcha)
  • JSON (for API functionality)
  • Multibyte String support (for internationalisation)

It is recommended that you increase the memory available to PHP threads beyond the standard 8 or 12M, and increase the maximum uploaded filesize (which defaults to 2M). In both cases, this can be found in your php.ini.

Recommendations for plugins

• The following PHP libraries are also recommended for some plugins and extra functionality:
  • SOAP
  • DOM