X11R6 contains sources for a number of X servers from XFree86, Inc.:
XF86_S3, XF86_Mach8, XF86_Mach32, XF86_8514, XF86_Mono, XF86_Bdm, XF86_SVGA,
and XF86_VGA16.  See xc/programs/Xserver/hw/xfree86.  Also included in R6 is
Xsvga from SGCS and Thomas Roell; see xc/programs/Xserver/hw/svga.  All of
the above are Unix-based.

X11R5 already provides a server to many 386/486 *Unixes* with support for
many of the popular video graphics adapters; and for other non-MSDOS PCs you
can obtain a server from these sources:

XFree86 (formerly X386 1.2E) is an enhanced version of X386 1.2, which was
distributed with X11R5; it includes many bug fixes, speed improvements, and
other enhancements. Source for version 2.0 [10/93] is on ftp.x.org in
contrib/XFree86 or ftp.physics.su.oz.au in /XFree86.  In addition, binaries
are on ftp.physics.su.oz.au, and ftp.win.tue.nl among other systems. Info:
x386@physics.su.oz.au.  Note: this package obsoletes Glenn Lai's Speedup
patches for an enhanced X11R5 server for 386 UNIXes with ET4000 boards
(SpeedUp.tar.Z on ftp.x.org).

Metro Link Inc. (305-970-7353, sales@metrolink.com; in Europe contact ADNT,
(33 1) 3956 5333) ships an implementation of X11R4 for the 386/486 Unix
market.

SGCS offers X386 Version 1.3, based on Thomas Roell's X11R5 two-headed
server, in binary and source form. Information: 408-255-9665, info@sgcs.com.

ISC, SCO, UHC, and other well-known operating-system vendors typically offer
X servers.

For MSDOS PCs:

Daniel J. McCoy compiled a list of non-UNIX servers for PCs, Macs, and
Amigas; it includes pricing information. The file is on ftp.x.org in contrib
as XServers-NonUNIX.txt.Z; it dates from 4/93.

X-Deep/32, for  PCs running Windows 95 or Windows NT 3.5+, includes an X
Server, basic X11 clients and client libraries. A demo copy is at
http://www.eden.com/~pexus/ and
ftp://ftp.eden.com/pub/users/pexus/export/xdeep32.zip . Information:
info@pexus.com.

An article on PC X servers appears in the March 2, 1992 Open Systems Today.

Also of possible use:

Net-I from Programit (212-809-1707) enables communication among DOS, OS/2 and
Unix machines and can be used to display PC sessions on your Unix X display.

Tektronix has a product called WinDD which allows Windows "protocol" to
display on an X display; see
http://www.tek.com/Network_Displays/Products/windd.html .