GNU/Linux is totally different from Windows so a "PrimoCache for Linux" would effectively be a new product, which would then have to offer support for multiple GUIs (KDE, Gnome, ICEwm, Enlightenment) and potentially interact with multiple file systems (Ext 2/3/4, ReiserFS, ZFS).
In addition it would have to compete against
existing free tools. So while possible, it would seem very difficult to see how a "PrimoCache for Linux" could be commercially viable.