At its annual CustomerWorld conference, Siebel released Siebel Component Assembly for Microsoft .NET.

The announcement is the follow-up to a 2002 agreement to support Siebel Universal Application Network (UAN) integration framework to Microsoft BizTalk, Microsoft Office, and to offer a client on Windows CE.

Siebel is unique in that the overwhelming majority of its customers are running on our platform, claimed Microsoft’s Tim O’Brien, senior product manager in the platform strategy group.

According to him, over 75% of Siebel customers run on Windows Server, and roughly 40% use SQL Server as the back end database.

With the new release, Siebel will offer prebuilt components for native integration with Microsoft Office 2003 editions, Office Outlook 2003, SharePoint, and Exchange.

It will support Visual Studio 2005 Windows Forms clients, plus native support for all of the .NET Framework technologies and web services.

The prebuilt components consist of a selection of libraries that developers can choose form, and configure using a visual workbench.

However, as the announcement covered product that is shipping now, it stops short of support of next generation Windows Vista smart clients, including the Windows Presentation Framework. However, Siebel has stated that it will support Vista for their next release.

The announcement of .NET support is interesting for Siebel because it diverges from Oracle’s J2EE-based Fusion roadmap. That means that, to support its existing base (which also includes a sizable IBM DB2 segment), Siebel will have to maintain dual technology integration roadmaps

However, as the latest player in Oracle’s growing stable, dual roadmaps aren’t totally without precedent. For instance, Oracle has publicly committed to supporting IBM DB2 for its JD Edwards customers.

And Oracle is maintaining a dual roadmap for its Java development tools, as it maintains its current product while ramping up an Eclipse line. And Oracle is a Microsoft Visual Studio Integration Partner (VSIP).