The likeliest program is an incarnation of Jef Poskanzer's useful++ Portable
Bitmap Toolkit, which includes a number of programs for converting among
various image formats. It includes support for many types of bitmaps,
gray-scale images, and full-color images. PBMPLUS has been updated recently;
the most recent version [12/91] is on ftp.x.org in
R5contrib/pbmplus10dec91.tar.Z.

Netpbm is based on the PBMPLUS 10dec91 release, with many additions and
improvements. It is intended to be portable to many platforms while allowing
for conversion of images between a variety of formats. The latest sources are
on several sites, including
ftp.x.org:/contrib/utilities/netpbm-1mar1994.tar.gz, wuarchive.wustl.edu
(128.252.135.4) and peipa.essex.ac.uk (155.245.115.161). Contact
oliver@fysik4.kth.se to be added to the netpbm mailing list.

xpdf, a Portable Document Format (PDF) viewer for X, is at (source and
binaries, especially Linux binaries):
http://www.contrib.andrew.cmu.edu/usr/dn0o/xpdf/xpdf.html
ftp://ftp.andrew.cmu.edu/pub/xpdf/
ftp://sunsite.unc.edu/pub/Linux/X11/xapps/graphics/viewers/ . Version 0.4
became available 4/96.

Certain pixmap editors (e.g. xpaint) can read in a variety of formats and
write out in different formats.

Another tool is San Diego Supercomputing Center's IMtools ('imconv' in
particular), which packages the functionality of PBM into a single binary.
It's available anonymous ftp from sdsc.edu (132.249.20.22).

Useful for viewing and converting some image-formats is Jim Frost's
xloadimage; the most recent [11/93] is on ftp.x.org in
R5contrib/xloadimage.4.1.tar.Z.  Graeme Gill's updates to an earlier version of
xloadimage are also on ftp.x.org; see xli.README and xli.tar.Z.uu; version
1.15 was released 7/93.

xv (X Image Viewer), written by John Bradley (xv@devo.dccs.upenn.edu for XV
questions), can read and display pictures in Sun Raster, PGM, PBM, PPM, X11
bitmap, TIFF, GIF and JPEG. It can manipulate on the images: adjust, color,
intensity, contrast, aspect ratio, crop). It can save images in all of the
aforementioned formats plus PostScript. It can grab a portion of the X
display, manipulate on it, and save it in one of the available formats. The
program was updated 5/92; see the file R5contrib/xv-2.21.tar.Z on ftp.x.org.
Version 3.10a [3/95] is distributed as shareware. New versions are on
ftp.cis.upenn.edu in pub/xv.

The latest revision of XAnim is 2.70.3 and can handle a wide range of audio
and video formats, including Quicktime, AVI, FLI, IFF, GIF, MJPG.  XAnim's
available from the XAnim Home Page at
http://www.portal.com/~podlipec/home.html or via
ftp://ftp.portal.com/pub/podlipec [3/96].

xa, an xview-based X11 animation tool by Derek Richardson
(derek@phaeton.ucsc.edu), is available at
ftp://ftp.x.org/contrib/applications/xa-1.2beta/ [5/96].

The Fuzzy Pixmap Manipulation, by Michael Mauldin (mlm@nl.cs.cmu.edu).
Conversion and manipulation package, similar to PBMPLUS.  Version 1.0
available via FTP as ftp://nl.cs.cmu.edu/usr/mlm/ftp/,
uunet.uu.net:pub/fbm.tar.Z, and ucsd.edu:graphics/fbm.tar.Z.

The Img Software Set, by Paul Raveling <raveling@venera.isi.edu>, reads and
writes its own image format, displays on an X11 screen, and does some image
manipulations.  Version 1.3 is available via FTP on ftp.x.org as
R5contrib/img_1.3.tar.Z, along with large collection of color images.

The Utah RLE Toolkit is a conversion and manipulation package similar to
PBMPLUS.  Available via FTP as cs.utah.edu:pub/urt-*,
weedeater.math.yale.edu:pub/urt-*, and freebie.engin.umich.edu:pub/urt-*.

Xim, The X Image Manipulator, by Philip Thompson, does essential interactive
displaying, editing, filtering, and converting of images. There is a version
in the X11R4 contrib area; but a more recent version (using R4 and Motif 1.1)
is available from gis.mit.edu (18.80.1.118). Xim reads/writes gif, xwd, xbm,
tiff, rle, xim, (writes level 2 eps) and other formats and also has a library
and command-line utilities for building your own applications.

ImageMagick by cristy@dupont.com is an X11 package for display and
interactive manipulation of images.  Includes tools for image conversion,
annotation, compositing, animation, and creating montages.  ImageMagick can
read and write many of the more popular image formats (JPEG, TIFF, PNM,
PostScript, ...).  Available via FTP from ftp.x.org as
contrib/applications/ImageMagick/ImageMagick3.7.tar.Z. [12/95] See also
http://www.wizards.dupont.com/cristy/ImageMagick.htmlZ .

GIMP is a General Image Manipulation Program. It is available at
http://www.csua.berkeley.edu/~gimp or via email to
gimp@soda.csua.berkeley.edu. It is currently [12/95] in beta.

xtiff is a tool for viewing a TIFF file in an X window.  It was written to
handle as many different kinds of TIFF files as possible while remaining
simple, portable and efficient.  xtiff illustrates some common problems with
building pixmaps and using different visual classes.  It is distributed as
part of Sam Leffler's libtiff package and it is also available on ftp.x.org
and comp.sources.x.  [dbs@decwrl.dec.com,10/90] xtiff 2.0 was announced in
4/91; it includes Xlib and Xt versions.

gpv is an image viewer with processing capabilities.  It uses Pacco to get
all the image processing support and it is coded entirely in TCL.  Gpv can be
fetched at ftp://iride.unipv.it/pub/Pacco/gpv-0.1.tar.gz . The latest
release of Pacco is at ftp://iride.unipv.it/pub/Pacco/pacco-0.9a7.tar.gz .
[8/96]

A version of Lee Iverson's (leei@McRCIM.McGill.EDU) image-viewing tool is
available as R5contrib/vimage-0.9.3.tar.Z on ftp.x.org. The package also
includes an ImageViewPort widget and a FileDialog widget.  [12/91;5/92]

The Andrew User Interface System (version 5.2 and later) provides an image
inset which can view many image formats.  Like all Andrew insets, an image
can be incorporated in a a document or sent in email via the MIME standard.
The following formats can be read:  Sunraster, GIF, Xbitmap,  TIFF, Xpixmap,
JPEG, PBM, XWD.

The LUG (Libreria de Utilidades Graficas) is a library of subroutines
offering several routines for the manipulation of images in several different
formats. The distribution includes viewers for several different platforms.
The distribution is on telva.ccu.uniovi.es (156.35.31.31):
/uniovi/mathdept/src/liblug-1.0.1.tar.gz.

The X Image Extension (XIE), an X Consortium standard in R6, provides
facilities for transmitting displaying fax (G3, G4), TIFF, and JPEG images.

[some material from Larry Carroll (larryc@poe.jpl.nasa.gov), 5/91]

A distributed real-time MPEG video and audio player is available from
ftp.cse.ogi.edu (129.29.20.2) in /pub/dsrg/Player/
(http://cse.ogi.edu/DISC/projects/synthetix/Player/ ) [5/95].