There are a variety of package systems.

Operating systems

package system tool web-based access
Ubuntu [[Advanced Packaging Tool|apt-get]], [[dpkg]] packages.ubuntu.com
Debian [[Advanced Packaging Tool|apt-get]], [[dpkg]] packages.debian.org
Red Hat Enterprise Linux [[Yellowdog Updater, Modified|yum]] rhn.redhat.com
Gentoo [[Portage (software)|portage, emerge]] packages.gentoo.org

Programming languages

package system tool web-based access
Perl cpan, cpanm search.cpan.org
Python [[Pip (Python)|pip]], easy_install pypi.python.org
Ruby [[RubyGems|gem]] rubygems.org
Node.js [[npm]] search.npmjs.org