Back in early 2003, I was learning C# by rewriting WiX v1, which was tens of thousands of lines of VBScript, to create WiX v2. At the same time, Jason Ginchereau was experimenting with C# to create a managed library to interface with the Windows Installer API. I didn't know about Jason's work at the time so we created a very limited interop layer in WiX to communicate with the Windows Installer APIs. Jason, on the other hand, worked until he had covered every aspect of managed code interop with the Windows Installer API plus support for reading/writing Cabinet and Zip files. He named the result the Deployment Tools Foundation (DTF):

Deployment Tools Foundation is a rich set of .NET class libraries and related resources that together bring the Windows deployment platform technologies into the .NET world. It is designed to greatly simplify deployment-related development tasks while still exposing the complete functionality of the underlying technology.

Over the last six months or so Jason and I have been working together more. You see, Jason is the dev lead on the Visual Studio team responsible for integrating the WiX toolset into the next release of Visual Studio. Among the various things Jason and I have been discussing is what to do with DTF.

The biggest hurdle was that there were not enough test cycles available to ship DTF as part of the next version of Visual Studio. Even though DTF was used by many teams inside Microsoft, all code that becomes part of a shipping product must have a certain level of verification by official test resources. Since there weren't enough resources available to ship DTF as part of the product, Jason was looking for alternatives. Joining the WiX toolset community was an interesting option.

The next hurdle was managed code Custom Actions. As noted above, the Deployment Tools Foundation has full support for the Windows Installer API. That means it is possible to create all types of Custom Action (immediate, deferred, impersonated, rollback, commit, you name it) using managed code.

However, a year ago I posted the outcome of the managed code Custom Action discussion I had with Carolyn (MSI Dev Manager) and a couple Windows architects. To sum up that blog entry they had two issues. First, the technical issue was that managed code Custom Actions needed to be run in a separate process. Second, the Windows platform has a strategic goal to reduce the number of Custom Actions.

When I posted that blog entry, DTF suffered from both issues. A month or so after the blog entry, Jason had addressed the technical issue by implementing the necessary interprocess communication mechanisms to move the managed code Custom Actions into a separate process but still be able to communicate with the Windows Installer. He did a very nice job keeping the overhead very, very low (a simple named pipe) and as a result his solution is very robust.

That left the strategic concerns. I struggled with one for a long time. On one hand, I could understand why they don't want to have a proliferation of Custom Actions. But, at the same time, I saw fewer and fewer native APIs being developed for fewer and fewer native code developers.

I think it was sometime over the week I took off for my birthday that I subconsciously decided what to do. The next blog entry I wrote was titled Obsolete skills where the subconscious decision finally bubbled to the surface. After that, I sat down with Jason and we discussed what it would take to integrate DTF into WiX.

Last night Jason finished the integration work and today you can find the Deployment Tools Foundation in the sdk directory of the latest Windows Installer XML toolset release.

Jason, thank you for all of your hard work and I look forward to watching DTF grow.