The code names for various subprojects within Windows 95


Most people know that Windows 95 was code-named Chicago. The subprojects of Windows 95 also had their code names, in part because code names are cool, and in part because these projects were already under way by the time somebody decided to combine them into one giant project.

Component Code Name
16-bit DOS kernel Jaguar
32-bit DOS kernel Cougar
Win32 kernel Panther
User interface Stimpy

Even when they were separate projects, the first three teams worked closely together, so the names followed a pattern of ferocious cats. My guess is that when the user interface team chose their code name, they heard that the other guys were naming themselves after cats, so they picked a cat, too.

I don't know whether they did that on purpose or by accident, but the cat they picked was not ferocious at all. Instead, they picked a cartoon cat.

Bonus trivia: When the feature to show a special message after Windows had shut down was first added, the shutdown bitmap was a screen shot of Ren and Stimpy saying good-bye. Fortunately, we remembered to replace them before shipping.

If you were paying attention: You would have noticed that code names get reused a lot, not because of any connection between the projects but purely by coincidence.

Comments (25)
  1. Mark says:

    So was Outlook also called Stimpy, or were all those guesses the from a few weeks ago off the mark?

    blogs.msdn.com/…/10522854.aspx

  2. Mark says:

    Oh, guess I've just proven even I can't read sometimes.

  3. kinokijuf says:

    …and Panther got reused, too.

  4. Joshua says:

    I have deep in my archives the message from Windows XP saying "It's now safe to turn off your computer."

  5. Jalopy says:

    so does this mean Mac OSX 10.2 was the 16 bit DOS kernel and 10.3 was the win32 kernel? I don't think they got to Stimpy before giving up on cat names

  6. morlamweb says:

    There may not be any relation between the various projects codenamed Stimpy, but one can infer that there are/were a number of R&S fans at Microsoft, just due to the number of references that have come to light recently.

    Raymond, thanks for another wonderful post.  I love these behind-the-scenes looks at the history of Windows.

  7. 12BitSlab says:

    Raymond, great stuff!  Over the years, have you contributed any of the code names for projects you worked on?

  8. dave says:

    Was the Win32 kernel derived from the sources of the 32-bit DOS kernel or the Windows/386 kernel?

    [I think Panther was based on the NT kernel but I'm not sure. Didn't realize there would be a quiz 20 years later. -Raymond]
  9. Yuhong Bao says:

    So the "32-bit DOS kernel" was the layer where all the VxDs ran and was equivalent to Win386 in Win3.x? And the "Win32 kernel" referred to Kernel32, VWIN32, etc…

    [Yes and no. Remember, these were the original code names prior to Win95. Things got redesigned after the components were merged into a single product. -Raymond]
  10. Yuhong Bao says:

    Looks like I am correct: groklaw.net/…/PX01285.pdf

    [Not sure how you concluded you were correct, seeing as there is no mention of VWIN32 in that document. -Raymond]
  11. "I am correct" is one of his postulates.

  12. Yuhong Bao says:

    [Not sure how you concluded you were correct, seeing as there is no mention of VWIN32 in that document. -Raymond]

    Not directly, but this mentions things like "thread support" for example.

    ["Thread support" is not the same as "kernel32, VWIN32, etc". At the time the cited document was written, VWIN32 did not exist. -Raymond]
  13. Joshua says:

    > "I am correct" is one of his postulates.

    Hmm leads to P∨¬P⊨Q very fast.

  14. smf says:

    Didn't the 32 bit kernel evolve from support.microsoft.com/…/83520

    [Not as far as I'm aware. -Raymond]
  15. Yuhong Bao says:

    @smf: Yea I am sure the "Win32 kernel" evolved from it. Remember the Win16Mutex?

  16. Joshua says:

    @smf: I'm inclined to think not.

    "If, for example, option A were using a CreateThread() call, then option B would be alternative code, which would handle the task using a single- thread solution."

    No, it's not proof but it sure suggests it. I'm vaguely disappointed CreateThread() wasn't there but it must not have been a problem in the tiny amount of Win32s programming I did.

  17. SomeGuyOnTheInternet says:

    Is it just me, or have .BAT files in Windows 8.1 just started executing lines that start with a semicolon?

  18. cheong00 says:

    @SomeGuyOnTheInternet : I think REMark for BAT file start with REM instead of semicolon.

  19. Mike Dimmick says:

    @SomeGuyOnTheInternet: Semicolon has never indicated a comment in a batch file, so far as I am aware.

    The "Command Shell Overview" page at technet.microsoft.com/…/bb490954.aspx says that ; and , are used for separating command parameters. This appears to work only with shell built-ins like 'copy' rather than as parameters to a program such as xcopy.exe. I recall Raymond mentioning the copy-with-two-commas to touch a file a while back: blogs.msdn.com/…/10432879.aspx

    Some answers at stackoverflow.com/…/how-can-i-comment-out-a-section-in-a-batch-file-and-how-can-i-add-comments-to say that you can use two colons, but I suspect this is another parsing bug. A single : introduces a label.

  20. slipstream says:

    Well, that solves some mysteries. The Comes vs Microsoft docs basically let me and others guess at what was jaguar/cougar/panther, however I didn't know that cabinet/cab32 (and probably more too, as UI is more than just shell I'm guessing) was codenamed "Stimpy".

    Now, if only pre-PDK1 chicago was widely available on the internet.. but of course hell would have to freeze over before that happens. At least we have that video from the b8 blog.

  21. NTAuthority says:

    I'd assume this is also why one early Win95 build that leake had either a startup or shutdown bitmap saying 'genuine Jaguar parts' :)

  22. slipstream says:

    NTAuthority, that'd be 58s (PDK1) and 73g (PDK2).. And it was a leftover startup bitmap from earlier in development when it used the *logo.rle. It's shown in that video from "George Wolfowitz" on youtube, but it is not known if the build depicted in said video is real or fake: http://www.youtube.com/watch

  23. slipstream says:

    By the way, Raymond, I once heard that before suwin, chicago used Jastro (the DOS/Windows combined setup). Was this true?

    And, on that note, was "Janus" the codename for Windows 3.1? It's listed as such all over the internet, but I haven't seen any proof relating to such.

  24. NT says:

    Speaking of classic versions of Windows, why doesn't Windows 7 have the classic Start menu that was included in versions Windows 95 up to Windows Vista?

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