Here's a tool to help you arrange your classes for next semester. Input the classes you want to take, and it'll tell you which schedules are compatible, if any. It pulls data directly from Harvey Mudd College's Portal, but it doesn't have to be used that way. In fact, it can be used for scheduling other things, too! Stores data on the client computer.
Here's a link to a working version. Thanks to Alex Ozdemir, Jonathan Chang, and Lisa Yin for improvements!