TonyMosa,

Yes Command Workstation 5.8 and the entire Fiery Extended Applications package fully supports El Capitan, as listed here:

http://www.efi.com/products/fiery-se...tion/overview/

The post above mentioning El capitan not being supported applies to Fiery XF server only, a completely separate product range which does not apply to your Ricoh Fiery server.