If this is for a website, the only way I can think of doing it, is to have two typographic CSS pages, one for mac, one for linux/windows.  But keep all other styles in one global CSS file.

 

Or you could use fonts which feature on all 3 operating systems.  I know I have experienced this, when wishing to use the Segoe UI font on Windows, and Lucida Grande for Mac OSX, with Lucida Grande being a larger font than Segoe.  This I assume has something to do with Macs using 72 dpi, and Windows 96 dpi.