PD-ksh is a mostly complete AT&T ksh (Korn shell) look-alike (see below for a list of things not supported). Work is mostly finished to make it fully compatible with both POSIX and AT&T ksh (when the two don't conflict).
Since pdksh is free and compiles and runs on most common UNIX systems, it is very useful in creating a consistent user interface across multiple machines. For example, in the CS dept. of MUN, pdksh is installed on a variety of machines including Suns, HPs, DecStations, pcs running Linux, etc., and is the login shell of ~5200 users.
PDksh is currently being maintained by Michael Rendell, who took over from Simon J. Gerraty at the later suggestion. A short list of things that have been added since the last public pdksh release (4.9) are auto-configuration, arrays, $(( .. )), [[ .. ]], variable attributes, co-processes, extended file globbing, many POSIXisms and many bug fixes.
Note that pdksh is provided AS IS, with NO WARRANTY, either expressed or implied. Also note that although the bulk of the code in pdksh is in the public domain, some files are copyrighted (but freely distributable) and subject to certain conditions (eg, don't remove copyright, document any changes, etc.).
The following is a list of machines that pdksh is reported to work on:
· -/PC Linux 1.x,2.x
· -/PC NetBSD 0.9a
· -/PC BSDI 1.1
· -/PC FreeBSD 2.x, 3.x
· -/PC OpenBSD
· -/PC Interactive/Sunsoft 3.0.1 and 4.1 (note that problems have been reported with isc3.2 - see the BUG-REPORTS file)
· -/PC OS/2
· Commadore/Amiga NetBSD 1.0
· Dec/alpha OSF/1 v2.x, v3.x
· Dec/alpha NetBSD 1.1B
· Dec/pmax Ultrix 4.2
· Dec/vax Ultrix 2.2 (not tested recently :-))
· Dec/vax 4.3BSD+NFS (MtXinu) (not tested recently :-))
· HP/pa HP-UX 9.01
· IBM/RS/6000 AIX 3.2.5
· MIPS/m120 RISC/os 5.0 (bsd43 environ)
· NeXT NeXTStep 3.2
· SGI/IRIX 6.2
· Sun/sun4 SunOS 4.1.3, 4.1.4
· Sun/sun4 Solaris 2.x
· Sun/sun386i SunOS 4.0.2
· Sun/sun3 SunOS 4.0.3, 4.1.1_U1
· Stardent/TitanOS 4.2