12 Like Cairo Shell Alternative? YES NO Cairo Shell is a replacement shell for the Microsoft Windows operating systems. Like other shell alternatives, it replaces the default Windows Shell. Cairo Shell will be free to download and use when it is released. Free Windows Discontinued While not officially stated as such anywhere since there is no blog or forum this project should be marked as discontinued. The code repository has seen no changes since 2010 and the site hasn't been updated since 2009 (check the copyright).