The new tool, Laszlo Webtop, runs on top of OpenLaszlo, an open source Web development platform.
"These applications [in the Webtop framework] all have to be OpenLaszlo applications. That's how we get the tight integration and performance," says David Temkin, co-founder of Laszlo Systems. "There's a lot of interoperability. ... Elements of one application can be dragged into other applications, just like a real desktop. You don't get that integration normally on the Web."
Unlike OpenLaszlo, Webtop is not free. Most businesses will pay at least US$100,000, including license fees, hardware and the cost of application development, company officials say.
Webtop also has a single sign-on function allowing users to log on to multiple applications with one password. Developers could place multiple applications in a browser with OpenLaszlo alone, but it requires writing more code, Temkin says.
"If you write a multiple-application desktop there's a lot of code to be written just to support that," he says. "The idea of having to implement a browser-based windowing system is not attractive to your average developer out there."
Webtop could be used to create software delivered as a service in various fields, like communications, business intelligence and customer relationship management, Temkin says.
Roundarch , a strategic partner of Laszlo, will be using Webtop to help its clients build Web sites. "They're giving you a framework and an ability to create the next generation of applications, applications that talk to one another," says Charles Fiesel, managing director of Roundarch.
Laszlo this week also announced the 4.0 version of OpenLaszlo, which is available for download. OpenLaszlo users include Gliffy, an online program that lets users draw and share diagrams, as well as Wal-Mart and H&R Block .
The biggest change in the new version allows Web developers to make interactive programs in a browser without using Adobe Flash Player. "It's just as interactive, just as animated, just as high performance ... but it doesn't' require the Flash Player," Temkin says.
That's not unique to Laszlo, though, says Jeffrey Hammond, a senior analyst at Forrester Research. "Just about every AJAX framework let's you use that," he says.