(Internet) A cross-platform, language-independent convention for representing and interacting with objects in HTML, XHTML and XML documents.

(programming) A programming paradigm that uses "objects" to design applications and computer programs.

Alternative spelling of object-oriented programming

(astronomy) a type of active galaxy with an active galactic nucleus (AGN), named after its prototype, BL Lacertae

(computing) An object in programming that provides an abstract interface to some type of persistence mechanism, providing some specific data operations without exposing details of the persistence layer.

(software) An individual database in the versioning software ClearCase.

(architecture, computing, design) A behavioural design pattern that describes the uses of null objects and their behavior (or the lack of them).

(programming, languages) An entity that can be constructed at run-time, passed as a parameter, returned from a function, or assigned into a variable.

(programming, languages) An entity of which the value can neither be passed as a parameter, nor be returned from a function, nor assigned to a variable. (Used by Raphael Finkel, the first-class object does not need to have run-time constructability according to his definition.)

(programming, languages) An entity of which the value can be passed as a parameter, but that can neither be returned from a function, nor be assigned to a variable. (Used by Raphael Finkel, the first-class object does not need to have run-time constructability according to his definition.)