This is a Debian Linux prepackaged version of the xtel Minitel X emulator.
Xtel was written by Pierre Ficheux <pierre@rd.lectra.fr>.
This package was put together by Christophe Le Bars <clebars@debian.org>.

Xtel is a X emulator of the french Minitel.

The Minitel is a dedicated terminal for accessing the Teletel,
the French videotex network.

The french Teletel network was created in 1980 by France Telecom, French
telecommunications operator. With it more than 20 million users can access
more than 25,000 on-line services. Users are billed as part of their telephone
bill, and France Telecom pays the service provider the appropriate amount
according to service usage and level (~0.10FF/mm - ~10.00FF/mm).

How can you see examples of videotex screenshots:
Select "charge enregistrement" in "Fichier" menu. Choose a file 
in /usr/doc/examples/xtel. Select "Lecteur" in "Enregistrement" menu...
You can now push the button "play".

For curious, there is a Internet/Teletel gateway: see http://www.minitel.fr
(This service isn't free, and i don't think you can use xtel with this gateway) 