Depends where your website is hosted, you will need php and mysql support iirc. I tried to get it to work (my host has what I needed), but it was too resource hungry and didn't work all that well.

It can use standard PHP image manipulation routines, or, add-one ones, the add-ons are much quicker, but can only be installed if your hosting provider allows you to. Mine doesn't so I was left with the standard poor performing ones...

PS: My host throttles resource which is why I had the problem.