I hadn't hear of calgo. I use AB for system design. There's an enormous amount of online resources for this.
Aussie stock forums has a dedicated AB thread for help. There's also the Yahoo AB groups, if you want to get really geeked out. Then there's the free library and online help which are both excellent.
It's fairy well accepted that for system development, AB is king. It can do anything so long as you can code it.
