It's a great pleasure to share with you the world's first online school scheduling/timetabling software done using Microsoft Silverlight. It's a software as a service available at: http://www.primetimetable.com.
Building this line of business application was a great experience as well as struggle, but as they say "all's well that ends well" :).
Hope I will have time to blog more about this experience.
In the mean-time, check it out, and let me know what you think about it.
I won't mind if you share this link with all your teacher/school master friends :), because school timetabling just got better!