I installed it on 1.0.15 with no trouble. I only needed it for registrations so that means I only had to replace/hack 3 core files. A lot of people complain about having to alter core Joomla files but that is the only way to implement captcha in registrations other than installing a separate registration component. If you're familiar with FTP and Joomla's file structure then the hacks shouldn't be a problem. However, upgrades might be a problem and require you to re-hack. I've tried many captcha solutions but this is the first one that really worked as promised.

It should be clearly stated that the Vodes component is made ONLY for automatic purchase of credits using PayPal and auto-adding of credits to a user account. It is not made for spending the credits! The credits are, however, stored in the database but you need some coding skills to implement a solution. The Documentation is sparse so if you can't get your hands dirty, stay away from this one.