It's a bit sad that Gentoo didn't promote this more, but Gentoo users now have support for license-based masking.

What does this mean? Well, previously, Gentoo already supported various masking reasons (like stable versus staging - the x86 versus \~x86 saga, package.mask'ing - for security reasons or critical bugs, ...). Now, a new feature is added: license masking.

By default, Portage accepts all non-EULA licenses. If a package uses a EULA license, you'll get a failure message stating that the license is 'masked'.

Now, what good does this do for users? Well, you can now ask Portage only to accept certain licenses (like @FSF-APPROVED, which is a list of all FSF-approved licenses) and deny the installation of others. Nice, isn't it?

I've added information regarding package license states (and the global as well as per-package unmasking support through /etc/portage/package.license) to the Linux Sea document.