KOffice was a free and open source office and graphics suite developed by KDE for Unix-like and Windows systems.

KOffice contains a word processor (KWord), a spreadsheet (KSpread), a presentation program (KPresenter), and a number of other components that varied over the course of its development.

Following internal conflicts, the majority of KOffice developers split off in 2010 – resulting in the creation of Calligra Suite.

In 1999, KOffice was cited in testimony in the United States v. Microsoft antitrust trial by then-Microsoft executive Paul Maritz as evidence of competition in the operating system and office suite arena.

[25] KOffice underwent a major transition as part of the release of KDE Software Compilation 4 (SC4).

The Krita painting application, the Kexi database manager, and dedicated mobile platform GUI files were not migrated into the KOffice git repository.

KOffice developers planned to share as much infrastructure as possible between applications to reduce bugs and improve the user experience.

[48] Automating tasks and extending the suite with custom functionality can be done with D-Bus or with scripting languages like Python, Ruby, and JavaScript.