Apple is hoping to make this year's Worldwide Developers Conference (WWDC), it’s most impressive, expansive event yet.

“It’s going to be the best Apple has ever done,” Richard Kerris, Apple’s director of developer technologies, told Macworld.

“It’s going to be the coming of age for Apple and Mac OS X”, he explained.

“We’ll be working aggressively to take developers into areas they’ve never seen before in our operating system and way of doing things.”

Kerris confirmed that Mac OS X is attracting a new wave of developers. Former Unix, NeXT and Java developers are moving in, and threatening to shake-up the industry.

“The number of developers moving to Mac OS X has exceeded our expectations by far,” he said. “It’s a wonderful feeling, but it’s extremely challenging. It’s hard to keep up with, but it’s a good challenge to have.”

Developer adoption is driven by Mac OS X’s advantages – its open-source Darwin core and Unix foundation open the doors to Mac for many former non-Mac developers.

“Developers are realizing that OS X isn’t what they were familiar with, and that it is actually Unix.’ This means existing proprietary applications built in Unix can simply be recompiled to operate on OS X.”

To good effect Richard Schlein, president of Tweak Films, confirmed Kerris’ claim. Tweak Films is a visual effects company with award-winning talent on staff. It’s famed for realistic water, fire and smoke simulations. Tweak is working on two feature films, scheduled for release this year.

Unix roots Schlein said: “Tweak’s artists and engineers have deep Unix roots, so we were quite sceptical at first. But months of careful evaluation proved that Mac OS X is the best choice for our company.

“The combination of a Unix infrastructure with mainstream desktop applications has “proven unbeatable, and Cocoa reduces the development time of our user-interface elements practically to zero.”

Unix developers moving to OS X can port existing Unix applications to it, mostly through a simple recompile. “Not only do Unix apps run on the platform, but they run better than on any previous Unix platform,” Kerris said.

Drawing on his film-industry past, Kerris, former head of Alias|Wavefront’s project to bring Maya to OS X, explained: “Most entertainment houses have traditionally had a Mac in the facility, but their workflow was on Unix-based machines.”

Production houses use off-the shelf systems, such as Maya, but many, such as Tweak, create proprietary Unix applications to apply their own unique dynamic and particle systems. Sony is among the largest studios considering porting its Unix apps to X, Kerris suggests.

The operating system is finding favour among scientists, too. “There’s great excitement in the scientific market,” Kerris revealed.

Apple’s Cocoa development environment is already popular. Dan Wood of Karelia Software – developer of Web utility Watson – explained: “Watson was built into a Cocoa app in just six months. It would have taken four or times that amount of time to build an equivalent product on another platform. It’s great to be able to leverage Unix-based technology in a great UI.”

Former NeXT developer Andrew Stone of Stone Design is a long-term advocate of Cocoa: “Once you’ve developed in that environment, you don’t want to go back.”

David Cook of Cookware is a new OS X convert: “I didn’t like Macs, they seemed prone to crash and didn’t multitask.”

He took the plunge with OS X and “was shocked”. So shocked, he stopped using his PC.

He said: “OS X is a dream.” My Mac hasn’t crashed in a year. I was pleased as punch; a box I could finally get into running Unix on that’s stable.” Now, Cook is learning Objective-C and Cocoa so he can create Unix code on his OS X Mac.

There’s a buzz in the Unix community, Kerris explained: “We have this grass-roots activity. Unix programmers and technicians communicate very well among themselves. News spreads like wildfire.”

A glance at open-source development Web site, reveals that OS X Unix component downloads are among the biggest on site. Development is happening in places Apple has never before reached, such as film companies and science labs, for example.

Building on OS X Apple expects a wave of high-end applications from Unix to reach the Mac OS. “Apps that have traditionally belonged to a very high end niche market will reach a broader market”, Kerris said.

The company recognizes the demand from architects and designers wanting solutions for their Macs: “Those using old antiquated Unix systems are pushing to get this stuff on OS X. There’s an opportunity for a developer to release such a package. It will get a great deal of attention.”

While Mac OS X offers much to Unix applications; it's a two-way street. Karelia Software’s Wood explains: “Watson makes use of a robust framework called CURL for fetching Web data that until recently wasn’t available for the Mac.”

Kerris explains: “I think some of the next wave of big applications are going to come from the garage. Our developer tools let one or two developers build what it once took 10-15 people to produce. Some really innovative tools will appear.”

The company is preparing itself for yet more developer attention. OS X offers the best Java support of any Mac OS yet. “We haven’t even touched on the 50,000 Java applications. It’s like you’ve invited friends over for dinner and the world’s knocking at your door,” said Kerris told Macworld.

Apple opened its first wave of retail stores last year, aiming to grab the 95 per cent of computer users that don’t use a Mac. Looking to developers, Kerris said: “We look at that other 95 per cent, and we want it.”

Apple’s Worldwide Developer’s Conference runs May 6-10 in San Jose, California. It will feature workshops, sessions and tutorials, including tracks on porting Java or Unix-based applications to Mac OS X. This interview was originally published in Macworld UK's April edition.