Mac::PropertyList::SAX is a Perl module to work with Mac plists at a low level (with real XML parsers).
Mac::PropertyList is useful, but very slow on large files because it does the parsing by itself, intead of handing off the actual XML parsing to a dedicated parser. This module uses XML::SAX::ParserFactory to select a parser capable of doing the heavy lifting, reducing parsing time on large files by up to 97%. This is especially useful for iTunes library plists which may be megabytes in size and contain thousands of entries in dozens of dictionaries.
This module does not, however, replace Mac::PropertyList; in fact, it depends on it for several package definitions and the plist creation routines.
Be aware that performance will depend largely on the parser that XML::SAX::ParserFactory selects for you; if you have not installed XML::SAX::Expat or another fast parser, the default XML::SAX::PurePerl parser will be used; this will probably give worse performance than Mac::PropertyList, so ensure that a fast parser is being used before you complain to me about performance :-). See XML::SAX::ParserFactory for information on how to set which parser is used.