mtt is a software utility, included in the xawtv packeage, which is used for viewing analogue and digital TV Teletext/Videotext. mtt has both a Motif-based GUI and a console mode. Having no channel changing capabilities of its own, mtt is a slave application that must be run in-conjunction with one that can provide tuning.
The version of mtt included in the 3.xx branch of xawtv only supports the handling of analogue teletext, whereas the version in the 4.xx branch supports both analogue and digital teletext.
In Debian, mtt is part of the motv package.