Xterm. It's been there for me since 1988, and I'm certain it'll be there right up until the eschaton in 2038. It's installed on every X11 system and it's alwa

Xterm. It's been there for me since 1988, and I'm certain it'll be there right up until the eschaton in 2038. It's installed on every X11 system and it's always compatible. (It has antialiased fonts, too.)