Software as a service--will that be with or without the client code? Software architects are grappling with that question, and business technology managers must be able to answer it.

RightNow Technologies, which until now delivered CRM applications as a Web service that required nothing more than a browser and a couple of plug-ins for access, last week introduced a new version of its product that does things differently. RightNow 8 includes a 15-Mbyte "smart client" that interacts with logic and data hosted on servers in RightNow's data center. Users must download the client to use RightNow's service. RightNow 8 features new design tools to customize its applications and a real-time customer feedback capability.

Ajax isn't enough, says RightNow CEO Gianforte

"Ajax and Web 2.0 are great technologies for casual use, but for mission critical you need the capabilities of a desktop app," RightNow CEO Greg Gianforte says. RightNow squeezed all it could out of Ajax and a browser, he says. When it comes to customer service, the few seconds of improved response time to be gained from putting code on a PC can be worth millions of dollars, he adds.

It's a subtle but important change in the software-as-a-service model, and not every vendor has embraced it. Salesforce.com, for one, doesn't require that all customers add applets to their PCs to make things work, though some must. To store contacts and leads locally, for instance, each salesperson who uses its service must download a lightweight "briefcase."

Expect to hear more about this software-design question in the months ahead, as application developers and customers assess the best approach. Getting Web software to coexist with client code on a PC, laptop, or smartphone will be a major theme of Microsoft's MIX developers conference in April and its Professional Developers Conference in the fall.

There already are many applications that live on the Web and require a download. Apple's iTunes is part-Web, part-Mac (or part-PC), as is Google Earth.

New tools help create such hybrid Web-PC applications. Adobe's forthcoming Apollo--runtime software embedded within an application--will let developers employ Flash, Flex, HTML, JavaScript, and Ajax in Internet-connected desktop applications, such as a desktop version of eBay that Adobe showed last month. And Microsoft's .Net Framework 3.0 was used to develop The New York Times' Times Reader, which lets readers access an online version of the newspaper without a browser and store articles to be read offline.