No deal has been signed yet and the companies are only in the "discussion" stages of an agreement, but the two companies have talked about incorporating the Castanet tuner software to Explorer 4.0's Active Desktop.
"We're definitely talking to them," said Arthur Van Hoff, the chief technology officer at Marimba.
A Microsoft source, however, characterized the talks as tentative, saying that there is "no deal in the works" between the two companies.
A deal with Marimba would be one of a series of Microsoft moves to outfit Explorer with "broadcasting" technology that brings constantly updated information directly to the user.
Earlier this month, the company cut a deal with PointCast, the pioneer in Internet broadcasting, to deliver its existing array of information channels to Explorer 4.0 users. The deal eclipsed an earlier agreement between Netscape Communications and PointCast. Microsoft also plans on negotiating separate deals with information providers.
Unlike PointCast, Marimba's primary aim is not to aggregate content into channels but rather to sell Castanet client and server software. According to analysts, a deal between Microsoft and Marimba could appeal to companies that want to broadcast networks for delivering corporate information and software.
Like other Internet broadcasting technologies, Castanet lets Web publishers "push" or automatically deliver news headlines, sports scores, and financial data to a special viewer application, rather than requiring users to manually visit a Web site for the same information.
The technology includes a Java-based tuner and server--called the Transmitter--that deliver information or Java applets. The client and server work closely together to ensure that the tuner always has the most up-to-date version of a news headline or program.
"PointCast software is distinct but forever tied to the PointCast server," said Harry Fenik, vice president of Zona Research. "For Marimba, there's a product there that they are trying to sell, not a built-in advertising network. PointCast is the trade name. I like the concept [of push technology] but I might want my own network."
Regardless of whether it signs a deal with Microsoft, Van Hoff said that Marimba would create a version of its tuner that functions as an ActiveX control on the Active Desktop, the broadcast feature with Explorer 4.0. The Castanet tuner, now in beta testing, is written in Java.
A Microsoft licensing agreement for the Castanet tuner would sharply increase the visibility of Marimba's broadcasting technology. Also, it would be further proof of Microsoft's vigilance in maintaining feature parity with Netscape. Netscape struck a similar deal with Marimba in October.
Netscape said it would incorporate the Castanet tuner into its Communicator upgrade of Navigator. Communicator will already allow users to receive Net broadcasts from regular Web servers through a feature called Constellation, but with the tuner built-in users would be able to take advantage of Castanet-based information networks.
A commercial launch of Communicator is expected by March.
Netscape and Microsoft aren't the only Internet companies interested in Marimba's technology. PointCast itself may find a way to leverage Castanet in its software.
In an interview last week, PointCast CEO Chris Hasset said that his company could easily partner with Marimba in the future if Castanet becomes more prevalent.
"Looking forward, if Castanet and their server products become the standard that we believe supports the network, we'll use it," said Hasset. "You can think of us as potentially being a huge customer of Marimba's."