Wikipedia
Extragear
The Extragear was the grouping name of software developed by the KDE project whose development and release schedule each is independent of other KDE software. Initiated for software duplicating functionality or being very specialized (like KSMSSend), with more and more powerful software like KDevelop or digiKam included in that group in later years the term seemed less and less fitting. Due to lack of common activity of the developers of software covered by that name, the corresponding website and mailinglist were dissolved in 2016.