Janus

[jey-nuh s] /ˈdʒeɪ nəs/

noun

an ancient Roman god of doorways, of beginnings, and of the rising and setting of the sun, usually represented as having one head with two bearded faces back to back, looking in opposite directions.

Astronomy. a moon of the planet Saturn, located just outside the rings.

Origin

< Latin, special use of jānus doorway, archway, arcade

British Dictionary definitions for Janus

Janus¹

/ˈdʒeɪnəs/

noun

the Roman god of doorways, passages, and bridges. In art he is depicted with two heads facing opposite ways

Word Origin

C16: from Latin, from jānus archway

Janus²

/ˈdʒeɪnəs/

noun

a small inner satellite of Saturn

Word Origin and History for Janus

ancient Italic deity, guardian god of portals, doors, and gates; patron of beginnings and endings, c.1500, from Latin Ianus, literally "gate, arched passageway," perhaps from PIE root *ei- "to go" (cf. Sanskrit yanah "path," Old Church Slavonic jado "to travel"). He is shown as having two faces, one in front the other in back. His temple in Rome was closed only in times of peace.

Janus in Culture

Janus [(jay-nuhs)]

The Roman god of doors and gateways and hence of beginnings.

Note: Janus was pictured with two faces looking in opposite directions, one young and one old. Consequently, a hypocritical person is often called “Janus-faced.”

Note: The month of January is named after Janus.

Janus in Technology

1. Distributed language with an ask/tell constraint system.
qdjanus is a Janus-to-Prolog compiler for Sicstus Prolog and jc is compiles to C.
["Janus: A Step Towards Distributed Constraint Programming", V. Saraswat et al in Logic Programming: Proc 1990 North Am Conf, S. Debray et al eds, MIT Press 1990].
["Programming in Janus", Saraswat, Kahn, and Levy].
2. W.M. Waite, U Colorado. Intermediate language, claimed as an implementation of UNCOL. Used on CDC 6600.
["Experience with the Universal Intermediate Language Janus", B.K. Haddon et al, Soft Prac & Exp 8(5):601- 616 (Sep 1978)].