By reducing development costs and making new features possible, cloud computing promises to create opportunities for software developers. A New York-based startup called Aviary is hoping to cash in on that promise by offering graphics programs that compete with far more expensive software.

Founded in 2007, Aviary uses Adobe’s Flex, a general-purpose platform for developing Internet-based applications, to make software that lets people modify photos, create illustrations, and share the results. Aviary’s applications run in Flash, through the Web browser on a user’s computer. Images are saved to the company’s private servers rather to a local disk drive–the conventional way of storing files. The private servers are continuously backed up to Amazon’s S3, a service that provides bulk online storage. If Aviary’s servers become overwhelmed because of, say, a glut of users, the system stays afloat by transferring files from S3 to users instead.

Aviary’s software development process has been the work of just a dozen or so programmers, and it has afforded a quick return on their effort. Because they can update the software as often as they like without requiring users to install patches or upgrades, a working version of an application can be rolled out the door as soon as it’s complete, with refinements made later. Matt Wenger, president and CEO of the software company GroupSystems, says that cloud applications can be cheaper to develop than other types of applications, especially because it removes the need to worry about how and where users install software. “You write one version of the application and you install it in your own controlled environment [on your servers],” he says, “and any changes are tested and rolled out in that environment. The net of it is that you spend hundreds of hours less in support over the life of a product for a group of customers.”

But while cloud computing can make product development and marketing more efficient, it has its own quirks. For example, Aviary needed a way to save huge image files quickly across a network. “An artist’s work flow generally requires frequent saving,” says Avi Muchnick, Aviary’s founder. “This means that we’d theoretically need the capability to send huge files multiple times in the span of a few minutes.” But constantly sending large image files back and forth over the Internet would strain Aviary’s servers and frustrate users with slow connections. The company’s solution is to detect incremental changes and transfer only those small pieces of the file that have changed.

Cloud computing provides more than just convenient storage. When artists allow people to use and modify their work through other media-sharing websites, the result can be a free-for-all. But ­Aviary tracks changes in images, so there is a record of how the work has been used. Artists can even levy royalties, which ­Aviary’s software enforces automatically. If a person creates an image and assigns it a royalty of 50 cents, and another artist incorporates it into a composite work and wants to sell it, the second artist would have to sell the composite image for at least 50 cents, with that money going back to the original creator. This easy royalty-sharing scheme creates a business model for artists that would have been impossible without cloud computing.

Aviary’s software offers fewer features than Adobe’s Photoshop and Illustrator, the gold standard among graphic designers and artists. But converts like Shawn Rider, manager of technology solutions at PBS, say they like it because they can access files from any Internet-connected computer and collaborate easily with other users, all for a very low price. Aviary offers access to a free version of its software with basic design tools. For $9.99 a month, users get more features as well as access to the royalty-sharing system.

Aviary also provides an application programming interface (API), which allows other businesses to integrate its image-editing tools into their websites. The New Yorker has used the tools for a cartoon contest, and the New York Daily News recently held a photo-editing contest to alter the image of Air Force One’s embarrassing flyover of New York City in April.

As for the future, Aviary is looking beyond image editing. In March, the startup acquired Digimix, a small company that makes Web software for audio editing; it may also start developing software for inexpensive online video editing, which should have a ready market among the hordes of YouTube contributors