As with every provider, the Parallels provider has a custom box format.

The actual list of official boxes provided by Parallels is available on wiki page.

All boxes from Parallels could be found on the "parallels" page on Atlas. You can also add and share your own customized boxes there. Read more on the Atlas Help page.

Discovering boxes

You can also look up all community Vagrant boxes for "parallels" provider and find the box matching your use case:

Adding a box from the catalog is very easy:

$ vagrant box add parallels/ubuntu-14.04

You can also quickly initialize a Vagrant environment with command:

$ vagrant init parallels/ubuntu-14.04