"In what will likely prove to be a controversial decision,
Portage 2.1 will adopt the RPM format for all packages moving
forward. The use of ebuilds will be deprecated in favor of the
defacto RPM standard. The primary driver for this decision was to
ensure compliance with the Linux Standard Base specification, which
mandates RPM support for package management.
"The developers have been hard at work to make this migration as
easy as possible. Already a proof-of-concept ebuild2rpm script is
in place and being tested by a pilot group of developers.
Unfortunately, because of the architectural differences between the
two formats, some features will not be supported once Gentoo moves
to RPM. USE variables are one such feature; sandbox security is
another. However, the added benefit brought about by full LSB
compliance should far outweigh the loss of these two minor