While ActiveX has enjoyed a (mostly) deserved reputation for being ill-tempered and hard to work with, I've used it successfully for many years as a deployment vehicle for rich-client web applications that run inside the context of IE. I'll attribute most of that success to Delphi and ActiveForms since the most complicated plumbing is taken care of for me automatically, but still gives me the ability to override what I need. Special thanks should go to Lino Tadros and Steve Teixeira, former members of the Delphi R&D team, to allow this.

Fast forward to today. My goal is relatively simple. I have a .NET application built with WinForms. I'd like the same type of ease of use in deploying this WinForm application to my users. I've done quite a bit of research on the best way to achieve this, but I haven't come up with the perfect solution yet. I'm close, but it's not buttoned up all of the way yet. For starters, I would highly recommend the following articles:

• Using Windows Forms Controls in Internet Explorer has a good overview of how to get a UserControl hosted in .NET
• Code Access Security and Distribution Features in .NET Enhance Client-Side Apps is a very complete article about hosting in IE. It talks about how to host an EXE, and gives some troubleshooting advice, including the fact that trying to host a WinForm (as opposed to a Control) will not work. :-(
• Deploy WinForms on the Web is a brief overview with some overlap, but has some good information.
• Security and Versioning Models in the Windows Forms Engine Help You Create and Deploy Smart Clients talks about how to deal with versioning, security, permissions, etc.

I wasn't able to find this nugget anywhere, though. If you want to call methods from your HTML page via (e.g.) JScript, you need to make your EXE assembly COM visible. The easiest way to do this is to select Properties for the EXE in the Project Manager, and press Assembly Information. There, you'll find a checkbox to make this assembly COM visible.

So far, I've been able to get a WinForm EXE hosted in IE, strong-name it and communicate from the web page to the control. I still have several items left to tackle, like wrapping everything up in a CAB file for easier deployment, and getting calls to other assemblies working. I'll comment on those as I get to them, but if you have any pointers on better ways to do any of this, I'm all ears!