Jef Vlamings had an idea to build a calendar app called LiveCal, which was supposed to become a platform where you could share calendars. The whole idea was that calendars would become something you subscribe to. Due to the complexity of the idea and the lack of knowledge, the project never really took off.
However, he made a CSS3 calendar with some jQuery animation while he was working on the project. And then he has shared a nice tutorial on How to Create A Clean Calendar in CSS3 & jQuery.
Requirements: jQuery Framework and CSS3
License: License Free