course.mit.edu searches a fixed list of canonical locations for MIT webpages:
The default option, "I'm Feeling Lucky" checks to see if a user has previously saved a link to the class webpage.
The "Course Search" feature returns a list of all such webpages that are found to exist, and gives users an option of saving the correct link. Users are not allowed to save URLs of old stellar or OCW sites, but may still find the search results useful.
On January 1 and July 1 course.mit.edu is updated for the new term. Old saved urls are stored, and the next user to perform a course search will be given the option of saving a new url for that term.