This website contains links to software which is either no longer maintained or will be supported only until the end of 2019 (CKFinder 2). For the latest documentation about current CKSource projects, including software like CKEditor 4/CKEditor 5, CKFinder 3, Cloud Services, Letters, Accessibility Checker, please visit the new documentation website.
If you look for an information about very old versions of CKEditor, FCKeditor and CKFinder check also the CKEditor forum, which was closed in 2015. If not, please head to StackOverflow for support.
If you were using FCKeditor 2.x and now want to move to the new product line, CKEditor 3.x, you will quickly find that along with a complete code rewrite some of the configuration options have changed their names.
If you want to customize your CKEditor installation in the same way as you did with FCKeditor, use the Configuration Settings Mapping Between FCKeditor and CKEditor article to find a complete list of settings that are equivalent to what you are used to.