However, the options available in the administrative back-end to customize its behavior are limited. To modify the appearance of the chat-box, you have to modify the css files in the module directory (which isn't a big deal, in and of itself). Several style parameters are, however, hard-coded in the .js files (the vertical position of the chat box being one of them). Not an issue if you know what you're doing, of course, but I would have appreciated some styling options in the back-end.
On the other hand, I find the absence of an option to set the refresh behavior (rate, conditions) of the ajax calls the extension uses to check for users/messages a little more serious. On a site with only one user (the admin) connected, it sends requests every second or so. These are tiny, tiny requests, but I feel like I shouldn't need to modify files to restrict when and how often these ajax calls are made.
Nevertheless, this is a great piece of software, and well worth the purchase if it looks like what you need.
I used Fabrik to make database apps for several non-profit organizations who needed to store and track information about the clients that were passing through their programs. These organizations were using paper forms that had been around for years, and some were manually entering everything into these horrifying, bloated excel spreadsheets. "Unsophisticated" would be an understatement. It was my job to take their paper forms and excel monstrosities and figure out how to translate it all into an app for entering, viewing and managing client data.
I am by no means a professional, but with Fabrik I was able to design and maintain a stable, aesthetically pleasing and idiot-proof database app. Without the flexibility and sophistication of Fabrik this project would have been a nightmare.
Regarding support, I am a bronze subscriber and my experience with the Fabrik team has been uniformly positive. I recently ran across a bug (a simple 'oops' that they had apparenly overlooked). I made a post to the forum with the error message. Two hours later a new SVN rev was out, bug fixed. Thanks Hugh!
Frankly, I think I've been spoiled by the level of support. If a reply to a question doesn't happen within 24 hours I start to wonder if there has been some terrible accident. I'm only half-joking: support through the Fabrik forum has been very consistent and very good, and this has been the case for the past two years of using Fabrik for work and personal projects.
One minor critical note: Fabrik lets you do a wide variety of sophisticated stuff. With this flexibility comes a moderately steep learning curve. However, I think it's well worth your time to learn the ins-and-outs of this extension.