The file extension CWK stands for ClarisWorks, a widely-usedword processing program and productivity suite for Mac and Windows in the mid-1990s. ClarisWorks was later renamed AppleWorks, and then replaced by iWork. You may find a CWK file if you’re looking through files saved from an older computer. Since Apple no longer supports ClarisWorks or AppleWorks, without using a few tricks you may have trouble opening CWK files, unless you still have the program installed. Tips Writer Bio
