IBM Software has announced an update to the .NET support for their Informix database.  This update includes add-ins for VS2005, plus some big performance improvements.. 

A new data provider for Informix™ Client SDK V3.0 and its runtime product IBM Informix Connect Runtime (RT) V3.0 allows .NET applications to access IDS by using the common base classes that are declared in the System.Data.Common namespace. The .NET Framework 2.0 support for IDS V7.31, V9.4, and V10.00 on the Windows™ platform enables development of a generic .NET database application without referencing any data provider-specific classes. It provides IBM Database Add-Ins for Microsoft™ Visual Studio 2005, which is a collection of add-ins to the Microsoft Visual Studio .NET IDE, simplifying the creation of IDS applications that use the ADO.NET 2.0 interface. Client SDK V3.0 also contains significant performance improvements to the .NET data provider.

The full announcement from IBM is here.