However, the precompiled versions now requires a commercial license and there are other solutions.
Ghostscript
Capable of producing much lighter PDF files.
The basic principles involve converting your web page into a PostScript format using html2ps and then running it through Ghostscript to produce the PDF making use of the system() function.
PDML is built on top of FPDF, and is licensed under the GPL. It's a markup language ( similar to HTML ) parsed in PHP to dynamically create some PDF files.