(software) Of or relating to a product which is licensed to permit modifications and redistribution of its source code, as per The Open Source Definition.

(software) The practice of providing open-source code for a product. / (software) Open-source software in general. / (espionage) Information that is in the public domain and available to everybody.

A source of illumination.

(transitive) To release the source code of.

(in a packet switching network) A technique whereby the sender of a packet can specify the route that a packet should take through the network.

(programming) Human-readable instructions in a programming language, to be transformed into machine instructions by a compiler, assembler or other translator, or to be carried out directly by an interpreter.

(chiefly software) Whose constituent makeup, or source code, is not made publicly available.

(linguistics, translation studies) The language from which a translation is done. / (computing) The language of the source code to be compiled.

(scholarly studies) A written commentary which discusses previously produced original work of another author, especially a notable author.

(scholarly studies) An original work, especially one by a notable author whose work is now the subject of commentaries (secondary sources).