I think because they play very nicely with legacy software, without needing any modifications.  i.e the demo has unmodified, off-the-shelf versions of nginx, mysql and php.<p>The other unikernel projects (i.e. MirageOS and HaLVM), take a clean-slate approach which means application code also has to be in the same language (OCaml and Haskell, respectively). However, there&#x27;s also ongoing work to make pieces of the different implementations play nicely together too (but it&#x27;s early days).