S-TK is actually two components. First it is an immidiate mode GUI library, called SIUI (Singularity Immidiate-mode User Interface). Second is the Singularity ToolKit, which is a wObject Oriented Wrapper around the SIUI library.
  • SIUI library:
    • Simple C interface - inspired by the openGL interface
    • cross platform - works on any supported platform without need to change code