Claris Works data
CWK is a file extension for a Works data file format used by ClarisWorks productivity suite which became AppleWorks when Apple acquired Claris in 1998. CWK files may contain word processing documents, spreadsheets, drawings, or presentations.
CWK files are used under both names as well the Windows versions that existed of both, however AppleWorks has not been updated since 2004
Learn more about CWK files:
Visit the About AppleWorks support webpage.
Ask an IT peer about CWK files at IT Knowledge Exchange.