MELPA

MELPA is a growing collection of package.el-compatible Emacs Lisp packages built automatically on our server from the upstream source code using simple recipes. (Think of it as a server-side version of el-get, or even Homebrew.)

Packages are updated at intervals throughout the day.

To browse available packages, check out the archive index page.

Adding packages is as simple as submitting a new recipe as a pull request; read on for details.

Table of Contents

• Usage
• Contributing
• Recipe Format
• Build Scripts
• API
• Mirrors
• About

Usage

To use the MELPA repository, you'll need an Emacs with package.el. Emacs 24 has package.el bundled with it, and there's also a version you can use with Emacs 23.

Enable installation of packages from MELPA by adding an entry to package-archives after (require 'package) and before the call to package-initialize in your init.el or .emacs file:

(require 'package)
(add-to-list 'package-archives
             '("melpa" . "https://melpa.org/packages/") t)
(when (< emacs-major-version 24)
  ;; For important compatibility libraries like cl-lib
  (add-to-list 'package-archives '("gnu" . "https://elpa.gnu.org/packages/")))
(package-initialize)

Then just use M-x package-list-packages to browse and install packages from MELPA and elsewhere.

Note: Packages from the default “bleeding-edge” repository will always have higher versions than those from other archives like Marmalade, so if you decide you need non-MELPA versions of specific packages for some reason, extra configuration will be required:

• If your Emacs has the variable package-pinned-packages (available in 24.4 and later), you can customize or modify that variable as needed.

• You can use the package-filter.el package which we provide.

• You can use MELPA Stable.

MELPA Stable

By default, MELPA provides the very latest revisions of packages. If you prefer to only receive updates for tagged releases, use MELPA Stable instead:

(add-to-list 'package-archives
             '("melpa-stable" . "https://stable.melpa.org/packages/") t)

Versions for packages on the original MELPA server are based on the date of the last commit and will likely be higher than any version on the stable server. Keep the following things in mind,

• If you leave the original MELPA server in your package-archives then by default you will get the development versions of packages and not the stable ones.

• You will probably want to remove all packages and then reinstall them. Any packages you already have installed from MELPA will never get "updated" to the stable version because of the way version numbering is handled.

Note that the MELPA maintainers do not use MELPA Stable themselves, and do not particularly recommend its use.

Contributing

See the CONTRIBUTING.md document.

Recipe Format

Packages are specified by files in the recipes directory. You can contribute a new package by adding a new file under recipes using the following form ([...] denotes optional or conditional values),

(<package-name>
 :fetcher [git|github|gitlab|bitbucket|bzr|hg|darcs|fossil|svn|cvs|wiki]
 [:url "<repo url>"]
 [:repo "github-gitlab-or-bitbucket-user/repo-name"]
 [:version-regexp "<regexp>"]
 [:module "cvs-module"]
 [:files ("<file1>" ...)])

• package-name a lisp symbol that has the same name as the package being specified.

• :fetcher (one of git, github, gitlab, bitbucket, bzr, hg, darcs, fossil, svn, cvs, wiki) specifies the type of repository that :url points to. Right now package-build supports git, github, gitlab, bitbucket, bazaar (bzr), mercurial (hg), subversion (svn), cvs, darcs, fossil, and EmacsWiki (deprecated) as possible mechanisms for checking out the repository. (Note: bitbucket assumes hg: git repos hosted on bitbucket should use the git fetcher.)

  package-build uses the corresponding application to update files before building the package. In the case of the github fetcher, use :repo instead of :url; the git URL will then be deduced.

  The Emacs Wiki fetcher gets the latest version of the package from http://www.emacswiki.org/emacs/download/<NAME>.el where NAME is the package name. Note that the :url property is not needed for the wiki engine unless the name of the package file on the EmacsWiki differs from the package name being built.

• :url specifies the URL of the version control repository. required for the git, bzr, hg, darcs, fossil, svn and cvs fetchers.

• :repo specifies the github/gitlab/bitbucket repository and is of the form user/repo-name. required for the github, gitlab, and bitbucket fetchers.

• :commit specifies the commit of the git repo to checkout. The value will be passed to git reset in a repo where upstream is the original repository. Can therefore be either a SHA, if pointing at a specific commit, or a full ref prefixed with "origin/". Only used by the git-based fetchers.

• :branch specifies the branch of the git repo to use. This is like :commit, but it adds the "origin/" prefix automatically.

• :version-regexp is a regular expression for extracting a version-string from the repository tags. The default matches typical version tags such as 1.0, R16 or v4.3.5, so you should not override it unless necessary. For an unusual tag like "OTP-18.1.5", we might add :version-regexp "[^0-9]*\\(.*\\)" to strip the "OTP-" prefix. The captured portion of the regexp must be parseable by Emacs' version-to-list function.

• :module specifies the module of a CVS repository to check out. Defaults to to package-name. Only used with :fetcher cvs, and otherwise ignored.

• :files optional property specifying the elisp and info files used to build the package. Please do not override this unless the default value (below) is adequate, which it should usually be:

    ("*.el" "*.el.in" "dir"
     "*.info" "*.texi" "*.texinfo"
     "doc/dir" "doc/*.info" "doc/*.texi" "doc/*.texinfo"
     (:exclude ".dir-locals.el" "test.el" "tests.el" "*-test.el" "*-tests.el"))
  

  This option is necessary when there are multiple packages in the repository and thus the package should only be built from a subset of .el files. For example, elisp test files should not normally be packaged. Any file specified at any path in the repository is copied to the root of the package. More complex options are available, submit an Issue if the specified package requires more complex file specification.

  If the the package merely requires some additional files, for example for bundling external dependencies, but is otherwise fine with the defaults, it's recommended to use :defaults as the very first element of this list, which causes the default value shown above to be prepended to the specified file list.

  Note that elisp in subdirectories is never included by default, so you might find it convenient to separate auxiliiary files such as tests into subdirectories to keep packaging simple.

Example: Single File Repository

smex is a repository that contains two files:

• README.markdown
• smex.el

Since there is only one .el file, this package only needs the :url and :fetcher specified,

(smex :repo "nonsequitur/smex" :fetcher github)

Example: Multiple Packages in one Repository

Assume we have a repository containing three libraries mypackage.el, helm-mypackage.el, and persp-mypackage.el. The latter two libraries are optional and users who don't want to use the packages helm and/or perspective should not be forced to install them just so they can install mypackage. These libraries should therefore be distributed as separate packages.

The three packages have to be declared in three separate files recipes/mypackage, recipes/helm-mypackage, and recipes/persp-mypackage:

(mypackage :repo "someuser/mypackage"
            :fetcher github
            :files ("mypackage.el"))

(helm-mypackage :repo "someuser/mypackage"
                 :fetcher github
                 :files ("helm-mypackage.el"))

(persp-mypackage :repo "someuser/mypackage"
                  :fetcher github
                  :files ("persp-mypackage.el"))

Example: Multiple Files in Multiple Directories

There are special cases where creation of the package comes from many different sub-directories in the repository and the destination sub-directories need to be explicitly set.

Consider the flymake-perlcritic recipe,

(flymake-perlcritic :repo "illusori/emacs-flymake-perlcritic"
                    :fetcher github
                    :files ("*.el" ("bin" "bin/flymake_perlcritic")))

which will result in a package structure of,

flymake-perlcritic-YYYMMDD
|-- bin
|   `-- flymake_perlcritic
|-- flymake-perlcritic-pkg.el
`-- flymake-perlcritic.el

Notice that specifying an entry in :files that is a list takes the first element to be the destination directory. These can be embedded further, such as the following---hypothetical---entry for :files,

("*.el" ("snippets"
         ("html-mode" "snippets/html-mode/*")
         ("python-mode" "snippets/python-mode/*")))

which would result in a package with *.el in something like,

package-YYYYMMDD
|-- snippets
|   |-- html-mode
|   |   |-- div
|   |   `-- html
|   `-- python-mode
|       |-- for
|       `-- main
`-- package.el

But a better solution, given that we probably want to copy the entire snippets directory to the root of the package, we could just specify that directory. Consider the pony-mode recipe,

(pony-mode
 :repo "davidmiller/pony-mode"
 :fetcher github
 :files ("src/*.el" "snippets"))

which generates the package,

pony-mode-YYYYMMDD
|-- pony-mode-pkg.el
|-- pony-mode.el
|-- pony-tpl.el
`-- snippets
    |-- html-mode
    |   |-- bl
    |   |-- ex
    |   |-- for
    |   |-- if
    |   |-- loa
    |   |-- sup
    |   |-- testc
    |   `-- {{
    `-- python-mode
        |-- auth-view
        |-- bn
        |-- model
        |-- modelform
        |-- render-to
        |-- testc
        `-- view

Build Scripts

Building MELPA is all based around using the Makefile included in the root repository directory. Described below are the actions that accepted by the Makefile.

• all -- Builds all packages under the recipes/ directory and compiles the index.html file for the melpa website.

• recipes/<NAME> -- Build individual recipe <NAME>. Built packages are put in the packages/ folder with version corresponding to the newest HEAD revision available; given according to the %Y%m%d format.

• json -- build all JSON files.

• archive.json -- construct the archive.json file that will contain a JSON object of all compiled packages.

• recipes.json -- construct the recipes.json file containing a JSON object of all packages available for building.

• clean -- clean everything.

• html -- build index.html.

• clean-working -- remove all repositories that have been checked out to the working/ directory.

• clean-packages -- remove all compiled packages from the packages directory.

• clean-json -- remove all JSON files.

Note that these scripts require an Emacs with package.el installed, such as Emacs 24. If you have an older version of Emacs, you can get a suitable package.el here.

API

All repository code is contained in the file package-build/package-build.el. That code is maintained in a separate repository: the version in the MELPA repository is imported using git subtree.

Functions

• (package-build-all) : build packages for all recipes in the directory specified by package-build-recipes-dir.

• (package-build-archive NAME) : interactive elisp function to build a single archive. NAME is a symbol for the package to be built. Packages are staged in the directory specified by package-build-working-dir and built packages are placed in the directory specified by package-build-archive-dir. Packages are versioned based on the most recent commit date to package files based on commits to upstream package repository. For multi-file packages, the file <NAME>-pkg.el is automatically generated and contains description, version, and requires information determined by searching <NAME>-pkg.el, <NAME>.el, and <NAME>-pkg.el.in, if they exist in the repository.

Variables

• package-build-working-dir : Staging area containing package repositories and package directories being built.

• package-build-archive-dir : Location to store archive-contents and any built packages.

• package-build-recipes-dir : Directory containing MELPA compatible recipes. See Recipe Format section for more details.

Configuration

Packages end up in the packages/ directory by default. This can be configured using the package-build-archive-dir variable.

Repositories are checked out to the working/ directory by default. This can be configured using the package-build-working-dir variable.

Mirrors

We are not responsible for the contents of any unofficial mirror of our packages.

Official mirrors are available (with many thanks to mirrorservice.org) so that if melpa.org is down, packages can still be installed. The following are the HTTP/HTTPS URLs to use in package-archives for MELPA and MELPA Stable respectively:

• http://www.mirrorservice.org/sites/melpa.org/packages/
• https://www.mirrorservice.org/sites/melpa.org/packages/
• http://www.mirrorservice.org/sites/stable.melpa.org/packages/
• https://www.mirrorservice.org/sites/stable.melpa.org/packages/

Only the packages are mirrored, not the web site front-end itself.

About

MELPA is Milkypostman's ELPA or Milkypostman's Experimental Lisp Package Archive if you're not into the whole brevity thing.