Opus numbers

Opus

[oh-puhs]

Opus is a Latin word for work. The plural of opus is opera. It is used in many fields, notably in architecture and in music.

In music, pieces of music by composers are given opus numbers, which generally run in order of publication. Unpublished compositions often are given WoO numbers (Werk ohne Opuszahl, German for work without opus number).
In architecture, it specifically describes a technique or a method or a style of connecting building elements, following the studies on Roman architecture. Roman building styles are commonly classified as:

Opus incertum
Opus testaceum (also called Opus latericium)
Opus caementicium
Opus reticulatum (also called Opus certum)
Opus siliceum
Opus quadratum
Opus vittatum
Opus mixtum
Opus spicatum
Opus alexandrinum

In fine art, Opus is the formal name or nickname of a work of art

Magnum opus (or Opus magnum) refers to the best, most popular, or most renowned achievement of an author, artist, or composer. Magnum is Latin for big, large or great

Other uses

Region Hovedstadens Psykiatri#Opus teams is a treatment for early detection and intensive case management of young psychotic patients in Denmark
RiverOpus is a web platform by Technology 9 Labs
Opus is a document composition software for high volume printing by Elixir Technologies (www.elixir.com)
Opus (band) is an Austrian pop-rock group
Opus (brand) is a Brazilian shampoo
Opus (comic strip) is a comic strip by Berkeley Breathed starring Opus the Penguin
Opus is the name of an Australian magazine produced by Newcastle University Students' Association
Opus (microkernel) was a microkernel developed at Apple and later Taligent as the base for the Pink operating system
Opus bus is a model made by the Optima Bus Corporation
Opus Dei (God's work) is a Roman Catholic organization founded in 1928, which emphasizes the Catholic belief that everyone is called to be a saint and that ordinary life is a path to sanctity
Opus, Greece is an ancient Greek city of Eastern Locris, on the coast of mainland Greece across from Euboea
Opus (in alchemy) is a spiritual achievement from the soul's perspective
Opus International Group PLC is the corporate holding company for several engineering and consulting companies operating under the "Opus" brand name in several countries
OPUS card is a public transportation smart card in Québec which is going to be valid in a several cities around Montreal and Quebec.
Opus Pistorum is a novel by Henry Miller
Opus-CBCS is a Bulletin Board (Computer Based Conversation System)
opus String Quartet (real name is opus. with a period)
Opus College of Business is the business school within University of St. Thomas (Minnesota)
Opus is a Goan restaurant in Bangalore,India
Opus is a range of compressors supplied by Motivair (08450096161)
In some online forums, an Opus is a post announcing your intention to leave.
Opus III was an English techno group.
Opus (label) is a former Czechoslovakia state recording label based in Bratislava (now Slovakia).
Mr. Holland's Opus is a 1995 dramatic film about a retiring band director, starring Richard Dreyfuss.
Opus Performing Arts Community is a Community Theatre Group based in South Australia.