Yes but this depends upon you having access to an Internet Service Provider (ISP). That will allow you to run X-Windows applications on there system. My local Internet Provider (Vex) has X-Windows applications running on its server. So it's possible for me to run those applications and have the output sent to a Window on my Atari's X-Windows Desktop.

Update: Here's a simpler way suggested by Holger Janz (hjanz@informatik.uni-rostock.de) (http://www.informatik.uni-rostock.de/~hjanz/) (Thanks!)

• Before you connect to your ISP start up a Xvt session and issue the command "xhost +". If your Atari system has limited memory, issue an exit command to close the window after issuing the xhost command.
• dynamic SLIP/PPP connect to your ISP and then login with telnet my.favorite.Sun.Workstation
• finger on the telnet shell to get your IP
• setenv DISPLAY IP:0.0 on the telnet shell (tcsh syntax) - (Where IP is the address from the previous step)
• start your favorite X-Application as usually and it will appeare on your Atari's X-Windows Desktop.

Here is my old method incase you have problems with the above:

• Connect to your ISP. If you are using a dynamic SLIP/PPP connect be sure to note your LOCAL IP address that gets assigned to you.
• Start up a Xvt session and issue the command "xhost +" (without the quotes). (Note: This step can be done before you connect to your ISP.) This will allow any remote system to "write" output to your Atari X-Windows screen. If you want to save some memory after you issue this command you can exit to close the Xvt screen.
• Telnet to a ISP where the X-Windows Applications are located.
• Start the application as you would normally from the system prompt but add the following information: "-display local.ip.address.given:0.0 &" This is for a UNIX system, so the "&" makes this a background process. (To start: netscape the command is: netscape -display 204.92.52.3:0.0 & where 204.92.52.3 would be my local IP address when I signed on.) Again to save memory you might want to shutdown the telnet session.
• If you check out your modem lights you'll see there is all kinds of activity going on before you see anything. On my 14.4 modem it takes about 5 minutes for the Netscape window to appear. So I normally read some UseNet news while I wait.
• If you can run this way, you get the benifits of HTML+ (JPG, centering, forms, etc.) PLUS pages with a lot of graphics is no longer an issue as most of the dirty work is being done by your ISP rather than your Atari computer!!
• Keep watching this space as I'll update/revise/simply this procedure as I learn more.
• You can use the exact same procedure to start up Xclock, Xtrek, Xetc.