My Current Development Stack

Here is the stack that I use per January 2010

IDE
I'm using Visual Studion (.NET) 2008

Language
C# is my main programming language. Use less and less VB.NET nowadays.

UI / Presentation
ASP.NET with Infragistics controls, or:
Windows application also with Infragistics controls. I'm still using standard Windows Forms, not WPF (Windows Presentation Foundation)

Business Layer
Although lot of projects I currently maintain now are mostly in Spaghetti code, I already start to use Spring.NET frameworks. The projects structure also replicating Spring project's structure

Data Access Layer
The abuse use of SqlConnection is excessive in my current projects, so I start to use iBatis.NET in new project. So far so good!

Database Server
Mainly using SQL Server 2008. But specific to Times Software, we also using Advantage Database Server. The ugly truth is, you cannot use Advantage with iBatis.NET

Source Control
SVN

That's my development stack.

PS: on my leisure time, I learn Java (with JSF and facelet) on MySQL database. I build a simple application to maintain my movie collection using this stack. Pretty good I must say.