What is "meiryo"

is a Japanese sans-serif gothic typeface. Microsoft bundled Meiryo with Office Mac 2008 as part of the standard install, and it replaces MS Gothic as the default system font for Vista on Japanese systems.

It was decided that a new Japanese font was needed, as the current ones (mainly MS Gothic and MS Mincho) are incompatible with Microsoft's ClearType subpixel rendering technology: Meiryo is intended to increase legibility of characters on LCD screens. ClearType has been available in Windows for Latin fonts since the release of Windows XP in October 2001. However, unlike Latin fonts which use the ClearType hinting system for all sizes, the Japanese fonts distributed with Windows included embedded bitmap versions of the fonts in small sizes. Although fonts using only hinted CJK glyphs exist (such as Arial Unicode MS), they had not been distributed with Windows prior to Vista.