Ebuild

An ebuild file is Article description::a text file, which identifies a specific software package and tells the Gentoo package manager how to handle it. For each available version of a package, there is an ebuild in the [[repository to allow it's installation.]] Ebuilds use a bash-like syntax style and are standardized through the Package Manager Specification, by adhering to a specific EAPI version.

Ebuilds contain metadata about each version of a piece of available software (name and version, license, home page address, etc), dependency information (both build-time as well as run-time dependencies), and instructions on how to build and install the software (configure, build, install, test...).

The default location for ebuilds in Gentoo is the Gentoo ebuild repository.

ebuild command
is also the Portage command for running the various ebuild functions. Information can be found locally by running:

Live ebuilds
An ebuild is a live ebuild if the source is fetched from a revision control system (VCS). They tend to, but not necessarily, have the version number 9999 so that they can be easily distinguished from normal ebuilds based on upstream releases.

In a formal sense, an ebuild is live if it has a variable  with a value "live" inside it. If an ebuild inherits a VCS eclass (e.g. git-r3, mercurial, darcs), it will be live, because these eclasses have a line.

In the site packages.gentoo.org, a Live ebuild has the sign L. In the output of eix, it is marked with.

External resources

 * Ebuild eclass reference in the developer manual.
 * ebuild-maintainer-quiz.txt - Gentoo developer ebuild quiz.
 * ebuild - ebuild man page.