In 2004, when equinux began developing its first consumer product, iSale, CEO Till Schadde says that the company consciously set out to create an application that would complement and work seamlessly with the applications on Mac OS X, including Apple's iLife suite.

Two years later, the company’s first consumer product has been a smash success, and the team at equinux feels that the opportunities are enormous.

Schadde says, “The Mac market is growing fast, and every Mac user is a potential customer. Apple has done a great job creating this wonderful ecosystem, and with all the tools and technologies that make it easy to create new applications, we’re working on plenty of new things. We’re planning to double the size of our development team.”

Selling items on eBay, particularly for first-time sellers, can be an intimidating experience. A successful selling tool needs to feature a user experience that’s seamless and familiar.

Till explains, “When you want to organize and listen to music, you use iTunes. When you want to organize and share your photos, you use iPhoto. And when you want to sell things online, you use iSale.”

By building iSale to work with the wide range of applications and technologies that are included with Mac OS X (e.g., Mail, Address Book, Spotlight), equinux was able to rapidly ship a sophisticated product that customers already knew how to use. iSale’s attention to detail and intelligent use of Mac OS X development tools have resulted in both sales success and two Apple Design Awards.

iSale helps customers with a task-selling items on eBay-that can be extremely rewarding but also daunting. First-time and low-volume sellers are often overwhelmed by eBay’s process, which requires multiple decisions and steps to complete a successful sale. iSale’s approachable interface makes the first few sales seem incredibly easy, especially for users who may have first tried to sell items using eBay’s online interface.

iSale’s effectiveness and simplicity lie in how easy it is to create an attractive eBay listing, which the user sees almost immediately, and this is where developing for Mac OS X paid big dividends. By using the WebKit framework to display an exact preview of the listing, complete with all the eBay elements, iSale helps users quickly become confident that they are on the right track to selling their item.

Schadde explains, “iSale is all about improving the workflow for selling on eBay, and switching to a browser to preview a listing would have been yet another barrier. We didn’t want that, but we could never have justified the effort of creating our own HTML rendering engine. Even integrating one of the open-source options was daunting. Fortunately, WebKit is perfectly designed for use in Cocoa applications, so with a few lines of code and some nice HTML templates, we were able to add the eBay Preview right in the application, where it belongs.”

Another barrier to success for would-be eBay sellers is the process of adding photos to a listing. The equinux developers knew that, to simplify this process, they needed to take advantage of iPhoto and their customers’ iSight cameras. These tools make it easy to quickly add photos to a listing, and by also uploading images to a .Mac account automatically when the listing is published, sellers bypass the usual steps that eBay otherwise requires. For more experienced iSale users, especially high-volume sellers, integration with Address Book, Mail, and iCal are critical to managing the volume of communication required to be a responsive, successful eBay seller.

The common theme? Apple technologies made it easy for equinux to add features that help their customers enjoy success on eBay.

The Right Tools for the Job

The list of Apple technologies iSale uses is long, but Schadde says that equinux never set out to use every possible feature. Rather, the key is to find technologies that are appropriate to the task at hand.

Till says, “Even when Mac OS X Tiger shipped, we never once said, ‘Hey, that’s a cool technology; how can we use it in iSale?’ Our philosophy for iSale has always been to help users with a difficult problem, to make it as easy as possible to sell things on eBay. What’s so exciting about Mac OS X is that whenever we dream up new features for iSale, there are back-end tools available to help us implement them. Sometimes it seems like Apple has read our minds and figured out what we’ll need to make iSale work exactly the way we want it to.”

WebKit would be high up the list of critical application programming interfaces (APIs) that equinux used for iSale. Not only did it make the eBay Preview mode simple to develop, explains Ortwin Gentz, equinux CTO, it’s also central to the display of the auction editing view.

According to Gentz, “We make extensive use of the WebKit in iSale. For example, we use the editable Web View, which I think is uncommon. It helped us to allow the user to edit an auction listing using a template, and the user can see everything as it will look in a live listing, but with drop zones for pictures, text fields for them to edit, and so on. Some things, like the picture drop zones, aren’t built into the WebKit, but we were able to extend it to add this functionality. And this lets users edit their listings directly, looking almost exactly as it will be on eBay itself.”

By using industry-standard HTML to create templates and print layouts for the WebKit framework to display in iSale and use as the interface for entering new auction listings, equinux designers can, working independently of engineering, quickly customize iSale to add views tailored to specific item categories, without making changes to the application itself. These features go beyond just eye candy; by adding additional text fields or drop zones, along with prompt text, interface designers can craft different user interfaces without needing to take software developers away from other tasks. And Gentz says it isn’t just equinux’s graphic designers who can create new templates or print layouts.

“We give users the ability to create and edit their own templates,” Schadde explains. “The template language is HTML, with just a few custom tags that we created to define things like text fields and drop zones. And this all comes almost for free because we’re using the WebKit framework and a little glue to connect the custom tags to the required auction fields.”

Because WebKit renders standards-based HTML, end users can use virtually any HTML editing tool to customize iSale for their own businesses or processes.

High-Velocity Development

What might be even more impressive than iSale’s powerful user interface is how quickly equinux developed the product. Although the company was already an established Mac OS X developer, iSale was to be its first product for the consumer market. And equinux decided to launch iSale at Macworld Conference & Expo 2005, less than two months away. Gentz says this decision made the project even more exciting.

Gentz says, “We started development just eight weeks before Macworld. And we were able to get that first version out; we shipped it at Macworld. It had all the core concepts of the application; it had the same compelling user interface, and it was a complete application. Cocoa made the whole system easy to develop and made it easy to follow an object-oriented design for writing the application. We fully anticipated that it would be possible to do it in eight weeks. Certainly there were some long days and nights, but we were sure it would be possible. And it was!”

The Cocoa framework makes it possible to create such a compelling user experience. Not everything comes directly out of Interface Builder, but Cocoa made it possible to build everything we wanted by creating custom views. It’s also nice to take advantage of the Cocoa elements you can use directly for things like preferences and so on.

APIs such as Spotlight—that were new with the release of Tiger—added value in some unexpected ways; for example, Spotlight let equinux add features that would have been difficult, or even not possible otherwise.

He says, “We use Spotlight to let users search within iSale for specific email correspondence. This is how we do most of our Mail integration. We rely on Spotlight being very fast; it lets us instantly display the relevant messages to a given auction. It wouldn’t be possible to do that by integrating with a custom search in Mail. The only other way we could be that fast would be to put an email client in iSale, and that’s not our mission. We want to integrate with the applications our users are already using.”

Substance, Style, and Speed to Market

iSale looks terrific on the screen—a compelling feature when it comes to selling copies of the application. But iSale’s appeal goes far beyond mere flash by giving users easy-to-use, powerful features for creating and managing one, a dozen, and even hundreds of eBay auctions. Creating a stylish application this powerful isn’t easy. According to Schadde, it’s not an accident that iSale is available only for Mac OS X.

Schadde says, “With Mac OS X, we get two things. First, there are the terrific technologies that make it easy to create good-looking, highly functional applications. That’s a given. But more importantly, we get applications like Address Book, Mail, and iPhoto and users who know how those applications work. The iLife applications aren’t APIs, but they are a big part of why iSale is on the Mac platform. Because users already know how to use Apple’s iApps, they already know how to use our software. This let us build a more sophisticated application without worrying that it would confuse our customers.”

iSale’s user interface is certainly a competitive advantage. The application has won the Apple Design Award for Best Mac OS X User Experience twice (in 2005 and 2006), which has certainly increased sales. For equinux, the extra attention that comes from having won an Apple Design Award is nice, but Schadde says it wasn’t critical to iSale’s success.

He says, “A little extra publicity never hurt anyone, but that only comes after you get your product off the ground and shipped. For us, we never could have created iSale without all of the help we got from Mac OS X itself. We knew if we created a compelling product, the rewards of selling on eBay would bring us customers.”

For more information about equinux and their products including iSale, see the equinux website.