IIRC XML::Parser::Lite is XML parser which supports subset of XML::Parser's API. Another difference is that XML::Parser::Lite is pure Perl module and XML::Parser is XS module which uses C library expat. Normally there is no reason to choose XML::Parser::Lite over XML::Parser since former is much faster and offers more capabilities. The only reason to use XML::Parser::Lite is that you have problems compiling XML::Parser on your platform.