Manual:$wgParserConf

Details
Associative array with the following members:


 * class
 * The parser class to use. Possible values are:
 * Parser: The new style parser using a separate preprocessor step. This is the default and recommended setting.
 * Parser_OldPP: The old style parser (as used in 1.11 and before). Compatibility option, not recommended.

The entire array will be passed through to the parser's constructor as the first parameter. Note that only Setup.php can use this variable -- the configuration will change at runtime via $wgParser member functions, so the contents of this variable will be out-of-date. The variable can only be changed during LocalSettings.php, in particular, it can't be changed during an extension setup function.

The new style parser accepts another configuration parameter:
 * preprocessorClass
 * The preprocessor class to use. Possible values are:
 * Preprocessor_DOM: Proprocessor implementation based on an XML DOM (requires PHP's XML module to be installed); This is the default
 * Preprocessor_Hash: Proprocessor implementation based on hashes (what does that mean, really?); Experimental. May be used of PHP's XML module is not available.