Zimbra on your Desktop Zimbra is doing this to support use of its Collaboration Server, which I think finally became compatible with Safari. (I need to doublecheck that.) Instead of using your browser, though, with Zimbra Desktop, you'd run Zimbra as a separate app, utilizing this new runtime layer. I'm not sure what I think of this new proliferation of such apps... following on Mozilla, Adobe, Microsoft, and so on, what's to be gained if users have to run multiple such runtimes to get their apps going? Isn't this taking us backwards instead of forwards? Just not sure...