Users who are still using OS X 10.4 (Tiger) and 10.5 (Leopard) are probably used to it by now, but yet another company has announced it is dropping support for the 10- and seven-year-old (respectively) operating systems. Dropbox, the well-known cloud storage firm that offers browser-based and native-app cloud storage for a wide variety of platforms, is informing users who access the service on the obsolete OS versions that support for them will end on May 18.