This page is accurate as of 2006-08-07 for building older KDE stable versions. Other pages containing similar information are being consolidated to here. Please help me find any similar pages so I can consolidate them. This page is being actively updated, contact kde.org AT phor.net with any questions or hints.
Note: I don't know why you'd want to install older versions. Nonetheless, you've come to this page for that very reason. Please let me know what your motivation is so I can edit this page accordingly.