WPP is a small Perl script that allows preprocessing of HTML files. You can define variables, which are abbreviations for longer constructs, and include common HTML fragments. It's useful for giving an uniform layout to different HTML pages. It can be used into cgi-bin programs for automatic generation of pages. With less HTML code inside them you can make more flexible and readable scripts.
WPP provides four separate facilities that you can use as you see fit: inclusion of text/HTML fragments, variables expansion, conditional generation, macros expansion.