Ok, that was from clicking on a link in a web page.
When I run it from the command line, I get this: (stand back)
[bsl1@localhost download]$ mplayer video7.avi
Using GNU internationalization
Original domain: messages
Original dirname: /usr/share/locale
Current domain: mplayer
Current dirname: /usr/share/locale
MPlayer 0.90rc5-3.2 (C) 2000-2003 Arpad Gereoffy (see DOCS)
CPU: Intel Celeron 2/Pentium III Coppermine,Geyserville (Family: 6, Stepping: 6)
Detected cache-line size is 32 bytes
CPUflags: MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 0
Reading config file /etc/mplayer/mplayer.conf: No such file or directory
Reading config file /home/bsl1/.mplayer/config
Reading /home/bsl1/.mplayer/codecs.conf: can't open '/home/bsl1/.mplayer/codecs.conf': No such file or directory
Reading /etc/mplayer/codecs.conf: 50 audio & 136 video codecs
font: can't open file: /home/bsl1/.mplayer/font/font.desc
Font /usr/share/mplayer/font/font.desc loaded successfully! (206 chars)
Linux RTC init error in ioctl (rtc_irqp_set 1024): Permission denied
Try adding "echo 1024 > /proc/sys/dev/rtc/max-user-freq" to your system startup scripts.
Using usleep() timing
Can't open input config file /home/bsl1/.mplayer/input.conf : No such file or directory
Can't open input config file /etc/mplayer/input.conf : No such file or directory
Falling back on default (hardcoded) input config
Opening joystick device /dev/input/js0
Can't open joystick device /dev/input/js0 : No such device
Can't init input joystick
Setting up LIRC support...
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support.
You will not be able to use your remote control.
Playing video7.avi
AVI file format detected.
VIDEO: [IV50] 320x240 24bpp 30.14 fps 741.1 kbps (90.5 kbyte/s)
==========================================================================
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 22050 Hz, 1 ch, 8 bit (0x8), ratio: 22050->22050 (176.4 kbit)
Selected audio codec: [pcm] afm

cm (Uncompressed PCM)
==========================================================================
open: No such file or directory
vo_mga: Couldn't open /dev/mga_vid
open: No such file or directory
vo_mga: Couldn't open /dev/mga_vid
vo: X11 running at 1152x864 with depth 16 and 16 bpp (":0" => local display)
==========================================================================
Opening video decoder: [dshow] DirectShow video codecs
Win32 LoadLibrary failed to load: ir50_32.dll, /usr/lib/win32/ir50_32.dll, /usr/local/lib/win32/ir50_32.dll
Warning: DS_Filter() could not open DirectShow DLL. (DLL=ir50_32.dll, r=0x140)
Failed to create DirectShow filter
ERROR: Could not open required DirectShow codec ir50_32.dll.
Maybe you forget to upgrade your win32 codecs?? It's time to download the new
package from:
ftp://mplayerhq.hu/MPlayer/releases/w32codec.tar.bz2!
VDecoder init failed

Opening video decoder: [vfwex] Win32/VfWex video codecs
Loading codec DLL: 'ir50_32.dll'
Win32 LoadLibrary failed to load: ir50_32.dll, /usr/lib/win32/ir50_32.dll, /usr/local/lib/win32/ir50_32.dll
Can't open library ir50_32.dll
ICOpen failed! unknown codec / wrong parameters?
VDecoder init failed

*** Try to upgrade /home/bsl1/.mplayer/codecs.conf from etc/codecs.conf
*** If it still does not work, read DOCS/codecs.html!
Cannot find codec matching selected -vo and video format 0x30355649.
==========================================================================
Checking audio filter chain for 22050Hz/1ch/8bit -> 22050Hz/2ch/8bit...
AF_pre: af format: 1 bps, 1 ch, 22050 hz, little endian unsigned int
AF_pre: 22050Hz 1ch Unsigned 8-bit
AO: [oss] 22050Hz 2ch Unsigned 8-bit (1 bps)
Building audio filter chain for 22050Hz/1ch/8bit -> 22050Hz/2ch/8bit...
Video: no video
Starting playback...
A: 4.7 0.1% 0%
Exiting... (End of file)
[bsl1@localhost download]$
Dang, I just wanted to watch a simple avi...
Well, off to find some documentation to figure out how to not worry about remote controls and joysticks and how to get wincodecs and DirectShow stuff...

I would think that mplayer would give you at least just the basic capability to view an avi file.