This feature is included in the Solaris Express 9/03 release.
The Standard Type Services Framework (STSF) is a pluggable object-based architecture that allows users to access typographically sophisticated text layout and rendering. The pluggable architecture of the framework gives users the ability to use different font rasterization engines and text layout processors to achieve the desired visual representation. The pluggable architecture also manages fonts and enables application-specific fonts to be created. STSF includes both a standalone API and an X server extension to handle rendering on the server side for improved efficiency.
For more information about the project and how to use the API, see http://stsf.sourceforge.net.