Steve Jobs announced the release of Safari for Windows XP and Vista at this year's WWDC. This brings a few new pieces of Apple technology to the PC, in particular the font rendering which is used in Mac OS X. This produced quite a few interesting reactions (read Jeff Atwood's Coding Horror and Joel on Software), since Apple is using high quality sub-pixel glyph positioning.
High quality sub-pixel positioning is not compatible with crisp and pixel aligned character stems, which is the base for Microsoft's ClearType technology. Yes, I agree, Apple fonts look more blurry when compared to those rendered by Microsoft, but it cannot be avoided if you want to respect the font shape at any (possibly fractional) font size.
In Creative Docs .NET, I chose the same route as Apple: make sure that characters get positioned in the most precise way. However, my rendering algorithm simply relies on path filling as implemented by agg. I don't have access to the more subtle RGB smoothing used by both ClearType and Apple's font engine.