I've been working with CMS's for many years, right from the start with "Mambo", the transition and now Joomla! and over those years I probably used, tried and tested dozens if not hundreds of extensions, but when I first discovered Fabrik it blew me away. It is so much more then just another "Joomla! extension". At first hesitant as it sees a bit daunting, but it doesn't take long at all to catch on to the basics, which in no time lets you conceptualize, design and build highly functional Web-Applications!, which was just unthinkable for me before with my limited skills in php and sql. It is not only THE most powerful and flexible extension, but also THE most Empowering learning tool. I actually started now doing Database and Application design and that's only after just getting a bit familiar with Fabrik, I haven't even scratched the surface yet and can already see the possibilities are endless.
My highest regards and respect to those guys for such a great product, and mainly their dedication, passion and seemingly tireless support.
Even initially just using the free version lets you do amazing things.
I did purchase a subscription now and it is worth every penny and more then that!
Also the support is great, just looking through the forums shows that those guys really try to answer every question, and not just telling you "read the manual" but actually working with you for Your specific need and beyond that often adding some extra explanations that help you learn the application even more.
Additionally if you look at the SVN they are bringing out new features, improvements or fixes almost daily if not several a day, which makes you wonder if those guys ever sleep.
In short HIGHLY Recommended!! If you want to take your web development with Joomla! to a higher level, Try Fabrik!!