Secret unveiled : Why is the Whidbey release numbered 8.0.50727.42


The versioning scheme is 8.0.YMMDD.NN and that explains 8.0.50727. The mystery is with the build number .42. There are three top contenders for it, and no prize of guessing the correct one



  1. People were so impressed with my blog that they borrowed the number from my blog title

  2. Visual Studio 2005 is the answer to the universe. For people who have not read Douglas Adam’s, The Hitch-Hikers Guide to the Galaxy, buy a copy and read it.

  3. When we come close to the ship date we freeze everything else other than the dot build number, which gets incremented each time a new build is churned out. Incidentally the forty second build was the good bits that got shipped.

Comments (5)

  1. tim says:

    So, this build was baked way back on the 27th July? …

  2. Nope. This means that on 7/27 we had a build

    8.0.50727.00. This is the 42nd build after that….

  3. Al Gonzalez says:

    I thought the last number was considered the revision number – i.e. Major.Minor.Build.Revision.

    At least that is how it is described in the AssemblyInfo.cs file for the AssembleyVersion attribute.

  4. MSDN Archive says:

    The unfortunate thing is that our Beta 3 Refresh was almost 50727.42 as well, but the last 2 patches that I integrated were past the cut-off for that day’s build, so our Beta 3 Refresh build is, sadly, 50727.43 (I get to blame 2 bugs on Gauntlet I hit that day)

    No idea what our RTM build number will be – well over 100, I’d have to imagine, since we’re in the 60’s currently.

  5. atomic says:

    (I’ve responded to another .42 blog with a similar message…)

    It appears that .42 was not a coincidence as there are little bits of evidence in the RTM release. For instance, the .NET Runtime Optimization Service v2.0.50727_X86 is actually named (internally) as clr_optimization_v2.0.50727_32.

    Now, unless the _32 refers to 32-bit (which would be odd considering the remaining portions of the build number, and the inherent X86 reference), then it seems that RC was .26, and RTM was originally .32 but artificially pushed to .42.

    Also, Quan To’s "What’s with .42?" (http://blogs.msdn.com/quanto/archive/2005/10/27/486052.aspx) makes reference that the original code name for the .NET Framework was "Project 42". Hmm, interesting, eh!