http://www.trolltech.com

Let me start with, I do not work for Trolltech, I am just a happy customer. Qt is one of the best development environments out there. IMHO it is the best cross-platform development environment. It targets Mac OS X, Windows, and X11 (Linux and all the BSD's and other Unix-based OS's out there). There is also Qt-Embedded for PDA's, phones and other small embedded devices. It is C++ based and has a powerful form editor (Designer) as well as a very comprehensive API. It even provides platform independant API's for threading, networking, and database access (you are not required to use these, but they're very good). Qt also takes care of some design differences between the OS's. For example, on Macs, the menubar is still at the top. Button styles also follow the target's native look as well (although you can change this behavior).

Of course, the best part, is you can target multiple OS's with one development effort.

Yeah, or there’s RealBasic which does the same for those who want to use BASIC.

But the problem with all these alternative programming environments is that they will always be behind Apple’s own tools, particularly with each new rev of the OS.

Personally, i don’t like multi-platform programs because they are often constrained to the lowest common denominator. Apple has so many innovative Mac-only tools that you will always be better off sticking with Xcode.

Companies can be profitable by offering only Macintosh software. The question is, do you want to do one thing really well, or support the world and dilute the quality of your product? …And take on all the customer support headaches common on other platforms (e.g. Windoze) but largely absent on the Mac!

YMMV.

Qt is a bloody awful product, like every other attempt at a "cross-platform" GUI library. Just look at Google Earth on the Mac if you don't believe me.

Whenever you attempt to make a cross-platform GUI app, you end up with the least common denominator on every system you deploy it on. Write a native App, or please don't bother.

The problem the Mac faces is that most apps were originally developed for Mac, like Photoshop, Office etc. then the companies get greedy and port the apps over to PCs. Then the mac platform gets neglected and diluted to the lower quality OS,such as PCs.