An acronym for "object-oriented". (or was that "object-obsessed ?-) RS
Tcl abounds in extensions providing an object orientation (OO) programming style - see that previous link to read about incr Tcl and the others. See Category Object Orientation for additional relevant hits.
Further, there are activities such as object-oriented analysis (OOA) and object-oriented design (OOD) that concern themselves with analyzing a system (or a solution to a problem) in terms of objects and their behaviors.
"An object or two may sometimes be nice, just like a glass of beer. But one shouldn't start drinking at breakfast." (RS)
RS In a smokebreak, I whipped up this hierarchy of things, by weight:
Every "heavier" thing can contain zero or more of "lighter" things. And on each level one can implement "objects". Most use 4., TOOT uses 7. procs with -static variables could allow (some) OO in 5. Databases are (fat) objects at level 1.
Another shade of meaning for OO is
What: OO Where: http://www.cs.umn.edu/%7Edejong/tcl/OO.zip Description: OO extension that works in Tcl 7, Tcl 8, and Jacl. Updated: 08/1998 Contact: mailto:dejong at cs.umn.edu
As RS aptly observes in "interp alias", object methods can be described as syntactic sugar for a certain form of dispatching.