Here is the link to the developer, sounds like you can get code by contacting him. http://www.gagnews.net/post.php?pid=1
Update 19th March 2010 Wow! It kinda takes me aback that people are using mgCal after all. I will try to continue development of this applet to add more of the features I had planned originally. I do not have a N900 so cannot test how it runs on that platform. My focus will be the N810 which I have.