DrScheme is a graphical environment for developing programs using the Scheme,
MzScheme, and MrEd programming languages. DrScheme runs under Windows 95/98/NT,
MacOS, and Unix/X. 

 DrScheme's features include: 

     * Source text highlighting of syntax and run-time errors 
     * Support for multiple levels of Scheme from Beginning Student to
       Full Scheme 
     * An algebraic stepper for the Beginning Student language 
     * Interactive and graphical static analysis 
     * A graphical user interface (GUI) library 
     * Objects, threads, modules, exceptions, TCP/IP, and regular expressions,
       and filesystem support