The history of Kontact is much longer than the history of the current project known under the name Kontact. It evolved along with the technologies it uses and together with the community around the components it integrates.
KMail and KOrganizer were part of KDE almost from the beginning, as separate applications. When development for KDE 2 began the kdepim module was introduced. This started as playground for a reimplementation of the KDE address book which then became the KAddressBook of today and for an experimental new mail client called "Empath". KOrganizer moved into the kdepim module shortly before KDE 2.0 which was released in October 2000.
The first implementation of a KParts-based framework that aimed at integrating various existing components of personal information management software appeared in the KDE CVS on March 22th 2000. It integrated Empath and KOrganizer but never got to a state where it really did something useful.
In April 2002 the initial version of the Kontact framework was imported under the name Kaplan into the KDE CVS. It was the result of a weekend-hack inspired by the very modular plugin structure of what now is KDevelop 3 [36], which was at that time a brand-new rewrite of KDevelop 2. It integrated KOrganizer and KAddressBook. Shortly after that KMail was also integrated, and the resulting combination was released as Kontact for the first time as a stable preview release.
At the beginning of 2003 after a meeting of many of the core kdepim developers in Osnabrueck, Germany, KMail was moved into the kdepim CVS module, now combining all major components of Kontact in one module. KDE 3.2, in the beginning of 2004, was the first KDE release which included Kontact. This was version 0.8 and already provided a full set of features, mainly due to the long history of its components.
Since then kdepim is working towards the next release which will be Kontact 1.0. One interesting aspect is that the development communities of the different applications Kontact integrates also got integrated and now form a robust and powerful team which, just as Kontact itself, is more than the sum of its parts.