xsl

Move all the template rules that really are exactly the same into one module, common.xsl. Keep the ones that are different in separate modules, win.xsl and mac.xsl. In win.xsl and max.xsl add

<xsl:import href="common.xsl"/>

(Your URLs are not actually accessible, so this advice is without the benefit of looking at your code)

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference