The command M-x list-packages brings up the package menu. This is a buffer listing all the packages that Emacs knows about, one on each line, with the following information:

• The package name (e.g., auctex).
• The package's version number (e.g., 11.86).
• The package's status—normally one of available (can be downloaded from the package archive), installed, or built-in (included in Emacs by default). Package Statuses.
• Which package archive this package is from, if you have more than one package archive enabled.
• A short description of the package.

The list-packages command accesses the network, to retrieve the list of available packages from package archive servers. If the network is unavailable, it falls back on the most recently retrieved list. The following commands are available in the package menu:

h

Print a short message summarizing how to use the package menu (package-menu-quick-help).

?, RET

Display a help buffer for the package on the current line (package-menu-describe-package), similar to the help window displayed by the C-h P command (Packages).

i

Mark the package on the current line for installation (package-menu-mark-install). If the package status is available, this adds an I character to the start of the line; typing x (see below) will download and install the package.

d

Mark the package on the current line for deletion (package-menu-mark-delete). If the package status is installed, this adds a D character to the start of the line; typing x (see below) will delete the package. Package Files, for information about what package deletion entails.

w

Open the package website on the current line in a browser (package-browse-url). browse-url is used to open the browser.

~

Mark all obsolete packages for deletion (package-menu-mark-obsolete-for-deletion). This marks for deletion all the packages whose status is obsolete.

u, DEL

Remove any installation or deletion mark previously added to the current line by an i or d command (package-menu-mark-unmark).

U

Mark all package with a newer available version for upgrading (package-menu-mark-upgrades). This places an installation mark on the new available versions, and a deletion mark on the old installed versions (marked with status obsolete).

x

Download and install all packages marked with i, and their dependencies; also, delete all packages marked with d (package-menu-execute). This also removes the marks.

g

r

Refresh the package list (revert-buffer). This fetches the list of available packages from the package archive again, and redisplays the package list.

H

Hide packages whose names match a regexp (package-menu-hide-package). This prompts for a regexp, and then hides the packages with matching names. The default value of the regexp will hide only the package whose name is at point, so just pressing RET to the prompt will hide the current package.

(

Toggle visibility of old versions of packages and also of versions from lower-priority archives (package-menu-toggle-hiding).

/ a

Filter package list by archive (package-menu-filter-by-archive). This prompts for a package archive (e.g., gnu), then shows only packages from that archive.

/ d

Filter package list by description (package-menu-filter-by-description). This prompts for a regular expression, then shows only packages with descriptions matching that regexp.

/ k

Filter package list by keyword (package-menu-filter-by-keyword). This prompts for a keyword (e.g., games), then shows only packages with that keyword.

/ N

Filter package list by name or description (package-menu-filter-by-name-or-description). This prompts for a regular expression, then shows only packages with a name or description matching that regexp.

/ n

Filter package list by name (package-menu-filter-by-name). This prompts for a regular expression, then shows only packages with names matching that regexp.

/ s

Filter package list by status (package-menu-filter-by-status). This prompts for one or more statuses (e.g., available), then shows only packages with matching status.

/ v

Filter package list by version (package-menu-filter-by-version). This prompts first for one of the qualifiers <, > or =, and then a package version, and shows packages that has a lower, equal or higher version than the one specified.

/ m

Filter package list by non-empty mark (package-menu-filter-marked). This shows only the packages that have been marked to be installed or deleted.

/ u

Filter package list to show only packages for which there are available upgrades (package-menu-filter-upgradable).

/ /

Clear filter currently applied to the package list (package-menu-filter-clear).

For example, you can install a package by typing i on the line listing that package, followed by x.

A package can have one of the following statuses:

available

The package is not installed, but can be downloaded and installed from the package archive.

avail-obso

The package is available for installation, but a newer version is also available. Packages with this status are hidden by default.

built-in

The package is included in Emacs by default. It cannot be deleted through the package menu, and is not considered for upgrading.

dependency

The package was installed automatically to satisfy a dependency of another package.

disabled

The package has been disabled using the package-load-list variable.

external

The package is not built-in and not from the directory specified by package-user-dir (Package Files). External packages are treated much like built-in packages and cannot be deleted.

held

The package is held, Package Installation.

incompat

The package cannot be installed for some reason, for example because it depends on uninstallable packages.

installed

The package is installed.

new

Equivalent to available, except that the package became newly available on the package archive after your last invocation of M-x list-packages.

obsolete

The package is an outdated installed version; in addition to this version of the package, a newer version is also installed.

Packages are most conveniently installed using the package menu (Package Menu), but you can also use the command M-x package-install. This prompts for the name of a package with the available status, then downloads and installs it. A package may require certain other packages to be installed, because it relies on functionality provided by them. When Emacs installs such a package, it also automatically downloads and installs any required package that is not already installed. (If a required package is somehow unavailable, Emacs signals an error and stops installation.) A package's requirements list is shown in its help buffer. By default, packages are downloaded from a single package archive maintained by the Emacs developers. This is controlled by the variable package-archives, whose value is a list of package archives known to Emacs. Each list element must have the form (id . location), where id is the name of a package archive and location is the URL or name of the package archive directory. You can alter this list if you wish to use third party package archives—but do so at your own risk, and use only third parties that you think you can trust! The maintainers of package archives can increase the trust that you can have in their packages by signing them. They generate a private/public pair of cryptographic keys, and use the private key to create a signature file for each package. With the public key, you can use the signature files to verify the package creator and make sure the package has not been tampered with. Signature verification uses the GnuPG package via the EasyPG interface (EasyPG). A valid signature is not a cast-iron guarantee that a package is not malicious, so you should still exercise caution. Package archives should provide instructions on how you can obtain their public key. One way is to download the key from a server such as https://pgp.mit.edu/. Use M-x package-import-keyring to import the key into Emacs. Emacs stores package keys in the directory specified by the variable package-gnupghome-dir, by default in the gnupg subdirectory of package-user-dir, which causes Emacs to invoke GnuPG with the option --homedir when verifying signatures. If package-gnupghome-dir is nil, GnuPG's option --homedir is omitted. The public key for the GNU package archive is distributed with Emacs, in the etc/package-keyring.gpg. Emacs uses it automatically. If the user option package-check-signature is non-nil, Emacs attempts to verify signatures when you install packages. If the option has the value allow-unsigned, and a usable OpenPGP configuration is found, signed packages will be checked, but you can still install a package that is not signed. If you use some archives that do not sign their packages, you can add them to the list package-unsigned-archives. (If the value is allow-unsigned and no usable OpenPGP is found, this option is treated as if its value was nil.) If the value is t, at least one signature must be valid; if the value is all, all of them must be valid. For more information on cryptographic keys and signing, GnuPG. Emacs comes with an interface to GNU Privacy Guard, EasyPG. If you have more than one package archive enabled, and some of them offer different versions of the same package, you may find the option package-pinned-packages useful. You can add package/archive pairs to this list, to ensure that the specified package is only ever downloaded from the specified archive. Another option that is useful when you have several package archives enabled is package-archive-priorities. It specifies the priority of each archive (higher numbers specify higher priority archives). By default, archives have the priority of zero, unless specified otherwise by this option's value. Packages from lower-priority archives will not be shown in the menu, if the same package is available from a higher-priority archive. (This is controlled by the value of package-menu-hide-low-priority.) Once a package is downloaded and installed, it is made available to the current Emacs session. Making a package available adds its directory to load-path and loads its autoloads. The effect of a package's autoloads varies from package to package. Most packages just make some new commands available, while others have more wide-ranging effects on the Emacs session. For such information, consult the package's help buffer. Installed packages are automatically made available by Emacs in all subsequent sessions. This happens at startup, before processing the init file but after processing the early init file (Early Init File). As an exception, Emacs does not make packages available at startup if invoked with the -q or --no-init-file options (Initial Options). To keep Emacs from automatically making packages available at startup, change the variable package-enable-at-startup to nil. You must do this in the early init file, as the variable is read before loading the regular init file. Currently this variable cannot be set via Customize. If you have many packages installed, you can improve startup times by setting the user option package-quickstart to t. Setting this option will make Emacs precompute many things instead of re-computing them on every Emacs startup. However, if you do this, then you have to manually run the command package-quickstart-refresh when the activations need to be changed, such as when you change the value of package-load-list. If you have set package-enable-at-startup to nil, you can still make packages available either during or after startup. To make installed packages available during startup, call the function package-activate-all in your init file. To make installed packages available after startup, invoke the command M-: (package-activate-all) RET. For finer control over which packages are made available at startup, you can use the variable package-load-list. Its value should be a list. A list element of the form (/name/ /version/) tells Emacs to make available version version of the package named name. Here, version should be a version string (corresponding to a specific version of the package), or t (which means to make available any installed version), or nil (which means no version; this disables the package, preventing it from being made available). A list element can also be the symbol all, which means to make available the latest installed version of any package not named by the other list elements. The default value is just '(all). For example, if you set package-load-list to '((muse "3.20") all), then Emacs only makes available version 3.20 of the muse package, plus any installed version of packages other than muse. Any other version of muse that happens to be installed will be ignored. The muse package will be listed in the package menu with the held status.

Each package is downloaded from the package archive in the form of a single package file—either an Emacs Lisp source file, or a tar file containing multiple Emacs Lisp source and other files. Package files are automatically retrieved, processed, and disposed of by the Emacs commands that install packages. Normally, you will not need to deal directly with them, unless you are making a package (Packaging). Should you ever need to install a package directly from a package file, use the command M-x package-install-file. Once installed, the contents of a package are placed in a subdirectory of ~/.emacs.d/elpa/ (you can change the name of that directory by changing the variable package-user-dir). The package subdirectory is named name-version, where name is the package name and version is its version string. In addition to package-user-dir, Emacs looks for installed packages in the directories listed in package-directory-list. These directories are meant for system administrators to make Emacs packages available system-wide; Emacs itself never installs packages there. The package subdirectories for package-directory-list are laid out in the same way as in package-user-dir. Deleting a package (Package Menu) involves deleting the corresponding package subdirectory. This only works for packages installed in package-user-dir; if told to act on a package in a system-wide package directory, the deletion command signals an error.