This WAS my favorite calendar tool for my desktop, but then all of a sudden it stopped appearing on my desktop in Snow Leopard. I don't know why, but since it wouldn't show up anymore then I decided to remove it. When it did work then it did a great job, but it isn't the most prettiest calendar and not much customization to it. I mainly like having the events listed and I'd usually make the horizontal calendar transparent (invisible).
The one thing I hated is if I made the horizontal calendar 7 days and my events list 21 days then if there wasn't anything listed in those 7 days then the events calendar would disappear. I always like being able to see what is coming up and I didn't really care for the horizontal calendar. So I had to add a bunch of days to the horizontal and make it transparent, so I could have my events list up.
The other complaint is that once that day came up then the event would disappear off the list and that can be a bad thing, because wouldn't you like to know what is due that day? Of course I could see it in the horizontal calendar, but I just didn't like the look to it and taking up my entire desktop. Also it looked strange with so many days in it.
I used busysync in conjunction of this program. I did this mainly to get google calendar updates into ical and then have icalviewer display my google calendar on my desktop. It worked great for awhile, but like I said it suddenly stopped working and I couldn't get it to appear on my desktop or even through its own window.
So I found a replacement for this program and it is called Rainlendar, which for whatever reason is not listed in macupdate. It is a cross platform based program and they have a free or pro edition. I got the pro version since it can get google calendar and ical in the same time. It pretty much seems to have everything this does and custom skins, so you can make it look as nice or as ugly as you want.
The only problem with rainlendar is if you lock it to desktop and decide to hide the tray icon and dock icon then adding events or todos is a pain. For whatever reason it will get hidden into the desktop and you can't click on the calendar. Only way you can click on it is by starting the program again OR waiting for an event alarm to pop-up. This isn't really an issue since I don't mind adding events through google directly and I have no reason to mess with the calendar on my desktop. I just need to be able to see it. The other nice thing is you can add a weather widget to it as well.
Right now it is only eating about 18 mb of memory and that isn't bad at all. Compared to icalviewer and busysync eating about twice or even three times more than that of resources. Also if you compare rainlendar is $13.00 while icalviewer is $11.00 and plus busysync is $39.00 which makes it $50.00 for the same thing that rainlendar can do already built in.
Also the nice thing is that it isn't tied to one OS that means your license works in Linux, Windows, and Mac. That might not matter to some, but if you change your mind and want it on your windows machine instead or linux then you have the option to move it without having to buy another license for that os.