On 2013-01-10 Glenn Fowler posted this to the ast-users mailing list:

As has been pointed out several times on the AST and UWIN lists, AT&T gives very little support to OpenSouce software, which is why we have so few people involved with our rather large collection of AST software. In spite of this, ksh, nmake, vczip, UWIN and other AST tools continue to be used in several AT&T projects.

It turns out that software isn't the only thing lacking support: both dgk (David Korn) (AT&T fellow, 36 years of service) and gsf (Glenn Fowler) (AT&T fellow, 29 years of service) have been terminated, effective October 10. Our third major partner, Phong Vo (AT&T fellow, 32 years of service), left a few months ago for Google. The UWIN maintainer, Jeff Fellin, is still with AT&T and provides UWIN support for some critical operations.

Both dgk and gsf will continue to work on AST software, and might actually have more time (at least in the short run) to focus on it.

The download site and mail groups will remain within AT&T for at least the next several months. Our AT&T colleague, dr.ek, AST user and bug detector, will maintain the site. We have secured the astopen.org domain and are investigating non-AT&T hosting options, including a repository with bug tracking.

The process of change will take time; the patience of the user community will be greatly appreciated. Its quite a shock to have 3 weeks to plan personal, career, and hacking futures after working in an environment that has essentially been stable for almost 30 years. The user groups will be informed as plans solidify.

Korn's own wikipedia page says he worked for AT&T Labs Research until 2013..., but he is now working for Googlecitation needed. A dgkorn github user account was created in November 2014, but it has been the source of exactly 0 public contributions since that time, and subscribes to as many repos.

Since 2013, the related mailing-lists have grown progressively less active. For example, the fourth-quarter ast-developers list for 2013 had posted 156 messages by 2013-12-01, but the same list for fourth-quarter 2015 lists only three messages, and this is the last of them:

Subject: Re: [ast-developers] Transitioning ast to GitHub

Is there any intention to transition the ast codebase to a source code repository like GitHub? That would make it much easier for the community to contribute. I'm concerned that without such a collaborative environment, ast-related development will stall as bug reports and source-code patches get lost in the ether.

Does anyone have a full git repo they can publish somewhere (repo.or.cz, github, whatever)? Git server is down for ages, now even www2.research.att.com ( went down.

This makes one wonder about the future of Kornshell. Has it died? Are we to see no more releases?

And, indeed, though AT&T lists all of the AST links at their labs research landing page, none of these seem to work. These are the same dead links listed at kornshell.com for download. Even if the current server state should prove only temporary for now, the dried-up mailing-list doesn't seem to bode well.

And so, is the korn shell now kaput? Or is there more activity along these lines elsewhere?

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    Obligatory: It's not dead. It's... pining for the fjords. Commented Nov 30, 2015 at 17:13
  • 1
    @mikeserv - alright, I'll put a protection on it so that it doesn't get a bunch of opinionated answers.
    – slm
    Commented Dec 15, 2015 at 4:32

4 Answers 4


It is not possible to give a real answer to this question, but the form of a comment is not sufficient. So I think it may be a good idea to collect points to a editable answer...

Two years ago, David and Glenn have been layed off by AT&T - I guess both are now over 65.

Half a year later, they have been hired by Google and Glenn confirmed me that their offices are beneath each other. It seems that they now have less time to answer questions in general.

I already sent a mail to Glenn in Summer 2015 and asked for a solution to the problem and he replied that he will try to do something. Two weeks ago (November 2015), I discovered that the AT&T download server was offline and sent another mail to both of them:

since some weeks, it seems that the AT&T website is not reachable anymore. 

http://www.research.att.com/software_tools forwards to 
and that forwads to http://www2.research.att.com/sw/download/ 
and the latter is unreachable from public.research.att.com. 

Given that www.research.att.com and www2.research.att.com are on the same  
subnet, I would guess that the machine has been switched off or it died and 
nobody cares. 

Unfortunately, archive.org cannot be used since the passwd requirements from  
the AT&T dowload site. 

Do you have an alternative download site set up already? 

I would like to let someone download and test UWIN. 

I did not yet get a reply on this mail.

Note that this year, I only received a reply from David, when this was a question for the POSIX standard committee that could only be answered by him (e.g. a question on the background of a design decision).

A mail I sent to Glenn Fowler on 2015-11-30, was successful and the download server at:


works again. Be sure to also check:


or the beta link in the left navigation bar to get the latest source from 2014-12-24.

Given that the download server did become inaccessible after a few hours and accessible again after people have been informed, we may be in hope that the problem is now known by the operators.

  • 4
    i found the glenn fowler repo. i dont feel bad about posting it either because i found it in an ast-list email from him. im pretty sure its the same thing as the other tarball. no UWIN, though.
    – mikeserv
    Commented Nov 30, 2015 at 15:58
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    www2.research.att.com/sw/download is now reachable. ksh release version there is 2012-08-01 ; beta version is 2014-09-29. Commented Nov 30, 2015 at 17:10
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    (113) No route to host for me
    – oals
    Commented Nov 30, 2015 at 21:38
  • 1
    Well, that was short-lived. I'll send mail to the admins. Commented Dec 1, 2015 at 4:17
  • 1
    The admins said that www2 is temporarily down for maintenance. Commented Dec 1, 2015 at 14:48


tldr: github.com/att/ast and github.com/att/uwin

On Jan 19-20, 2016 the following (1|2) messages were posted to the ast-users mailing-list: (and I consider the dgk has some patches comment especially encouraging)

Wed, Jan 20 2016; From Glenn Fowler:

Thanks Lefty for all the work getting this up and running. I know dgk has some patches in the works. He may be offline for the next few weeks.

Tue, Jan 19, 2016; From Eleftherios Koutsofios:

hi AST and UWIN users.

as many of you noticed, the download site on www.research.att.com went off the air shortly before the end of the year due to some security issue.

the timing was unfortunate because several people including me were on vacation so it's been down for a long time.

but we've finally managed to move most of that software on GitHub. you can find the AST and UWIN software packages at:

https://github.com/att/uwin and https://github.com/att/ast

(btw. the /att tree on GitHub hosts a lot of open source software developed by the AT&T Research group. feel free to browse. I'll be putting up some of my code there soon).

/att/ast corresponds to the ast-open package. it includes the software that was also available under individual packages, like ast-ksh, ast-dss, etc., so I decided to only create this one. it has 3 branches, matching the old structure: master (i.e. official), alpha, and beta. beta is the most recent one. it includes the last package I had gotten from Glenn and Dave with some minor fixes to get it to compile on some new OS versions, like Centos 7 and Ubuntu 14.

/att/uwin is the source code for the UWIN system. it has a master and a beta branch. I don't have an environment to build and test this on, so I don't know how well it builds.

cloning either of these git repos is equivalent to downloading the INIT and ast-open (or INIT and uwin) packages from the old site and then running:

./bin/package read

so the next step after the clone step is to run:

./bin/package make

vanilla build, where no previous version of NMAKE is available should still work and on some systems that was actually the way to go for me.

as an example, to get and compile the beta branch of AST:

git clone --branch beta \
cd ast
./bin/package make

very little of the documentation from the old site has moved to the GitHub site, I'll try to migrate the rest later, I just wanted to get the software up again.

thanks lefteris

  • 1
    Please note that you get ksh93u+ from this github location while the latest previous source was ksh93v-. ksh93u+ is from August 2012, ksh93v- is from December 2014.
    – schily
    Commented Feb 2, 2016 at 17:48
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    @schily - thats the master branch, yes. The differences are explained above.
    – mikeserv
    Commented Feb 2, 2016 at 17:55
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    @mikeserv Are minus (e.g., "ksh93v-") versions considered beta releases, then? And what does a "+" signify? Commented Sep 13, 2016 at 6:16

Yes and no. The official AT&T Korn Shell may be pining for the fjords, but there are two actively developed clones.

There's pdksh, the public domain clone of the Korn shell, but that hasn't been updated in 16 years, it seems. However, OpenBSD uses pdksh as the default /bin/sh and they update it fairly frequently. NetBSD's default install has pdksh as well.

There's also mksh (the MirBSD Korn Shell). It's the one your Linux distribution probably stocks.

The current version of mksh is mksh R51 from 10 July 2015.

  • 1
    I'm only responding to the question posed in the title. Someone might misunderstand that the official one is the only Korn Shell available.
    – oals
    Commented Nov 30, 2015 at 18:07
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    Solaris in release 11 has replaced the Bourne shell for its /bin/sh with ksh93, so at least Oracle will probably maintain a version of ksh93 (though maybe not opensource) for a while. Commented Dec 1, 2015 at 12:11
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    Sure, there are clones, but they're bad clones -- bash is catching up on ksh with respect to semantics/extensions, these days, but AFAIK no other shell (including mksh and pdksh) is even close to ksh93 with regard to runtime performance. Commented Dec 1, 2015 at 16:27
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    Do note that mksh (full disclosure: I’m its developer) regularily merges whatever OpenBSD does, as long as it makes sense.
    – mirabilos
    Commented Apr 8, 2016 at 22:29

"Yes and no. The official AT&T Korn Shell may be pining for the fjords, but there are two actively developed clones."

Unfortunately pdksh and mksh are ksh88 near workalikes (clone is too strong). I have yet to find an actual ksh93 workalike (bash and zsh don't come all that close).

Personally I hope that the transition to Google will speed up the release of ksh2k, but I have no inside information.

I'd hope that they would at least handle BSD and Linux out of the box (the vast collection of legacy systems supported by the current ksh93 base is perhaps best left to the various vendors to contribute to the new base).

  • Hi Keith, David told me that AT&T will not give permission to opensource a new product and thus the name ksh93 will stay forever. Do you have different information?
    – schily
    Commented Dec 11, 2015 at 17:27
  • No information, just wishful thinking. While ATT own ksh93 I don't know that they own ksh2016 ... even less likely that they'd own gsh (google shell) which could be ksh compatible ;> Commented Dec 13, 2015 at 3:23
  • Oh, and w.r.t. "mksh probably being the one your Linux distro probably stocks" CentOS provides ATT ksh (the EPEL repos provide mksh). Ubuntu provides ATT ksh as well. Is there ANY Linux distro which provides mksh when one asks to install ksh? Commented Dec 13, 2015 at 3:57
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    I meant it in the sense that "Your distribution is likely to have at least mksh in its repositories."
    – oals
    Commented Dec 17, 2015 at 11:42

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