Massachusetts Institute of Technology Professor Albert R. Meyer
6.044J/18.423J: Computability Theory of and with Scheme Fall, 1998

A Note About DrScheme

DrScheme is The Rice University Programming Languages Team's graphical user interface to a Scheme system for students. It is freely available and offers a Scheme programming environment which in many ways is better suited to students than MIT Scheme (even the MIT Scheme version tailored for 6.001 students).

DrScheme strives to be much more student-friendly than MIT Scheme. In particular, for nonexperts, debugging is much easier in DrScheme than MIT Scheme because DrScheme's error messages are clearer, and they indicate where in the user's source code the error occurred. In addition, DrScheme has "Analysis" commands which, for example, will highlight undefined variables in red and can display arrows from occurrences of variables to their definitions elsewhere in the code. It also has several output modes in addition to the standard one, for example, an output mode which shows sharing in lists, and another output mode in which values are printed as canonical INPUT expressions -- in this mode, for example, the list value which is the result of evaluating (cons 1 (cons (+ 2 3) '())) prints out as (list 1 5). DrScheme also has modern Windows 95 menu control of most features.

DrScheme has extensive online documentation which is, however, not always up to date. Its user interface favors working in a single Scheme file, which can make it less convenient for programs which load multiple files.

If you do use DrScheme, the 6.044 instructor would be very interested to hear what you think of it and to learn of any problems.


A Note About EdScheme

Edscheme has been developed for student use by
Schemers, Inc., a small Florida company founded by two high school teachers. It has been used successfully in high schools and colleges for several years. It strives to be much more student-friendly than MIT Scheme: text is color-coded to distinguish Scheme primitives, keywords, user definitions, constants, etc.; there are dynamic reminders (as you type in your program) of expected Scheme syntax and your syntactic errors; there is point-and-click lookup of previously entered procedure definitions; and it has modern Windows 95 menu control of most features, much clearer error messages, and convenient online documentation.

EdScheme is available for a free two week trial. (After the two week free trial, you have to buy a copy to continue using EdScheme. It lists for $130 but is promised to be available to 6.044 students for $68.95.)

If you do use EdScheme, the 6.044 instructor would be very interested to hear what you think of it and to learn of any problems.


Copyright © 1998 by Albert R. Meyer. All rights reserved. Last updated 10/28/98