On the php|architect blog today there's a new post about a tool that helps you create Word documents directly from your PHP application - PHPDOCX.
PHPDOCX is a PHP library that allows its client code to generate Microsoft Word documents in the .docx format from PHP scripts. PHP is increasingly being used for disparate goals and has to deal with data that comes from strange sources and has to be produced in stranger formats. [...] Starting with the 1.5 version, which has been released on July 12th, PHPDOCX is now compatible with PHP 5.3. The adoption of PHP 5.3 from operating systems is growing and it will at last replace the previous versions of PHP also in the servers of hosting providers.
He mentions some of the features it includes (like the library and automatic insertion of things like headers and footers) as well as two requirements for the tool to work - the zip and xsl extensions.