Has anyone ever build a more robust calendar?

Question

I am finding lots of custom calendar controls - but they are all pretty expensive. I'm wondering if anyone here has ever acheived the appearance/functionality of a Schedule/Calendar using the built in web/windows controls. I need something that will allow users to build a schedule pretty quickly, and allow others to see it/edit it as needed. Just hoping someone out there has had this task/problem before, and found a solution that worked for them. Thanks!