Mac vs Windows Anti-aliasing

When choosing fonts, it’s worth noting that how they look differs on Mac and Windows. By default, Macs anti-alias onscreen text, which affects spacing—in fact, various anti-aliasing algorithms can make text look slightly different in each browser. On Windows, aliased text has historically made for jagged edges, but Internet Explorer 7 smoothes type via the fontsmoothing technology ClearType, introduced in Windows XP (disabled by default in XP, but enabled in Vista system-wide).
For body copy, font-smoothing (or not) isn’t a major problem—although some prefer aliased text and some prefer anti-aliased, both are fine, as long as the font size is large enough. However, when it comes to rendering large text—such as for headings—aliased text is significantly less visually pleasing.Although arguments rage regarding which is the best method of displaying fonts onscreen, this is a moot point for web designers, because you don’t control the end user’s setup andtherefore must be aware of each possibility.