FreeType 2 is a high-quality and portable font engine that is capable of supporting several font formats (be they bitmapped or scalable) through a simple and uniform interface. Its design is modular and allows independent "font driver" modules to be added, even at runtime, to support additional formats. It also provides a high-quality anti-aliasing renderer, an innovative auto-hinting engine, and support for the following font formats: TrueType Type1, CID-Type 1, Multiple Masters Type 1 OpenType/CFF, pure CFF, and CEF Windows FNT/FON.
rxvt-unicode is a clone of the well known terminal emulator rxvt, modified to store text in Unicode and to use locale-correct input and output. It also supports mixing multiple fonts at the same time, including Xft fonts, real transparency, and an optional embedded Perl interpreter that allows you to extend your terminal easily.
The DejaVu fonts are a font family based on the Bitstream Vera Fonts. Its purpose is to provide a wider range of characters while maintaining the original look and feel. The family is available as TrueType fonts and also as third-party packages for various operating systems, including handhelds.