Now that .NET 3.5 is out for everyone's consumption, a customer buddy of mine asked:

Q. Should we deploy .NET 3.5 on our servers if we don't intend to use its features?

A. Hmmm, before I gave him a pat response (yes!), I decided to do some digging and here are the results. NOTE: It was still yes :) with the classic Microsoft preamble: It Depends and closing: YMMV.

Discovering a great KB Article (936704)

In my pursuit of the answer, I came across the following KB article that does a good job of describing what's new in .NET 3.5: Benefits of the Microsoft .NET Framework

• WCF and WF integration
• Durable WCF services
• Partial trust support for WCF in targeted scenarios
• WCF Web programming model (JSON)
• WCF Syndication (Atom and RSS)
• WF rules improvements
• WCF interoperability for updated standard XAML Browser Applications (XBAPs)
• WPF Interactive 3D API and 2D on 3D API
• Increased WPF XBAP integration with browsers to enable unified cookie access
• WPF UI Add-Ins Model
• Firefox support for XBAPs

My only complaint with the article is that it is missing a graphic to show the dependency that 3.5 and 3.0 have on 2.0:

Perhaps they should have incorporated the Green Bits vs. Red Bits graphic from http://www.danielmoth.com/Blog/2007/06/net-framework-35.html.

Should we patch .NET 2.0?

Back to the task at hand. I wasn't about to tell my buddy to patch 2.0 to SP1, instead I led him to the conclusion by showing him that 2.0 SP1 contains several fixes that his ASP.NET applications might want. In fact, Problems that are fixed in the .NET Framework 2.0 Service Pack 1 lists at least 26 ASP.NET related fixes. Time to review...

Should we patch .NET 3.0?

Since they had 3.0 installed on the servers but were not using it (WF, CardSpace, WPF) other than WCF, should they patch 3.0 to SP1? Again, I didn't want to overstep my bounds, so I asked my buddy to review the 9 entries in Problems that are fixed in the .NET Framework 3.0 Service Pack 1 that had ominous sounding keywords: “hang”, “slow performance”, “various problems”. Time to review...

All roads lead to patching 2.0, 3.0 (so why not install 3.5!)

In the end, I think my buddy will be convinced that patching 2.0 and 3.0 makes sense. Since .NET 3.5 redist neatly packages the 2.0 and 3.0 service packs, lets hope he takes the most pain-free route: installing.NET 3.5 on the servers.

Go get .NET 3.5 from here!

Aren't you glad you are running Visual Studio 2008? You are able to target 3.5, 3.0 and 2.0!