Objects
In HTML programming, building blocks of a page (paragraph, image, sound, ActiveX components...)

OCR
Optical Character Recognition. Technology used to identify characters in a digitised document.

ODBC
Open DataBase Connectivity. Standardised interface, or middleware, for accessing a database from a program.

Offline Browser
Software used to save all or part of a Web site onto a user's hard drive.

OLE
Object Linking and Embedding. Microsoft technology that enables the creation of documents by incorporating elements created using different kinds of software.

OpenType
Microsoft font types support technology.

Opera
Small Web browser, competitor of Netscape Communicator and Internet Explorer, which supports style sheets and JavaScript.

Option or Radio Buttons
User interface elements placed in a form to provide a limited number of options, from which only a single reply can be selected.