Several replies to the question about group theory texts mentioned ISETL and "Exploring Small Groups". For what its worth, I'd like to mention some other group theory course-related software called "Group Analyzer" which I have used in my own junior-level abstract algebra course.
"Group Analyzer" allows students to perform a variety of standard elementary calculations with specific groups (and homomorphic images of any of their subgroups). It is designed to help students work with small and medium sized examples (up to order 400) much in the spirit with which they work very small examples by hand. Students can use examples to formulate conjectures and find counterexamples. "Group Analyzer" gives students exploratory tools without over-automating the process.
"Group Analyzer" can be downloaded from the Mathematics Archives at http://archives.math.utk.edu/ . It runs on Macintoshes and it is free. The archive includes some of the worksheets I used in my course last year (LaTeX format).
Paul Glenn Department of Mathematics Catholic University of America Washington, DC 20064 email: firstname.lastname@example.org