As the others have basically stated; I found AT unusable for a project I had.

Roths stuff is good as long as you don't try it on W2K. From what I have been told is that he is way too busy to keep things current these days.

One nice little prize I found on sourceforge is TaskScheduler. It is being developed but I found it usable and the author is very interested in making it work.

So if you want a good alternative, give it a look!