Distributing AppImages

There are several ways to distribute AppImages to users. Most likely, AppImages are distributed from their creator to the users.

The following section contains some details on how AppImages are commonly distributed.

Hosting AppImages

Most commonly, AppImage creators host the files on a standard webserver. This is the easiest and most accessible way.

We recommend that you put the AppImage for Linux on your project’s download page alongside the dmg for macOS and the exe for Windows, like so:

Download page overview, showing Windows, MacOS, Linux and Source code downloads

For open source projects, if your project is located on GitHub, we recommend that you publish your AppImage in addition on GitHub Releases.

Note

For AppImageUpdate to work properly, it is required that the web server supports HTTP range requests. Most web hosts support this, as the same technology is used for navigating an MP3 files, for example.

Some hosted services are known not to support range requests right now. These involve:

If you use such a service and wish to use AppImageUpdate with it, please ask the providers to enable range requests.

Complying with licenses

Even under open source licenses, distributing and/or using code in source or binary form may create certain legal obligations, such as the distribution of the corresponding source code and build instructions for GPL licensed binaries, and displaying copyright statements and disclaimers. As the author of an application which you are distributing as an AppImage, you are responsible to obey all licenses for any third-party dependencies that you include in your AppImage, and ensure that their licenses and source code are made available, where required, together with the release binaries. AppImageKit itself is released under the permissive MIT license.

Do not put AppImages into other archives

Please DO NOT put an AppImage into another archive like a .zip or .tar.gz.

While it may be tempting to avoid users having to set permission, this breaks desktop integration with the optional appimaged daemon, among other things. Besides, the beauty of the AppImage format is that you never need to unpack anything. Furthermore, packing an AppImage into some form of archive prevents the AppImage from being added to the central catalog of available AppImages at https://github.com/AppImage/AppImageHub.

Making your AppImages discoverable

Now that you have produced your AppImage, you want users to be able to easily find it. To get users, you need to make your AppImage known to the world.

Application website

The most obvious place to advertise your AppImage is to prominently featured on your application’s download page.

Social Media

Also be sure to advertise your new AppImage on social media, for example on Twitter, blogs, etc. Be sure to use the #AppImage hashtag for additional discoverability.

AppImageHub

You may want to add your AppImage to AppImageHub, a crowd-sourced directory of available, automatically tested AppImages with data that 3rd party app stores and software centers can use. Given an URL to an AppImage, it inspects the AppImage and puts it into a community-maintained catalog.

App stores and software centers can consume the metadata collected by this project. See AppImage ecosystem.

Projects already using this data include:

To get your AppImage included, create a new file at https://github.com/AppImage/AppImageHub/new/master/data and send a pull request.

The file should contain one line with a link to the GitHub repository that hosts AppImages on its Releases page.

Alternatively, a link to the AppImage. Nothing else.

Then send a pull request. Travis CI will instantly perform an automated review of the AppImage, and in case it succeeds, you will see a green result in your pull request. If you get a red result, check the log of the Travis CI build, and fix it.

As a format, AppImage is designed in a way that does not impose restrictions on the person generating AppImages. Basically you are free to put inside an AppImage whatever you want. For AppImageHub, however, additional rules apply. AppImages submitted to AppImage hub undergo automatic and possibly additional manual review.

  • Must be downloadable from an URL. Our testing system fetches the AppImage using wget. Currently we cannot get AppImages from locations behind authentication and/or cookie-protected locations. For commercial applications we recommend to have a generally downloadable demo/trial version. Please contact us if you would like to add your commercial AppImage to the directory and it is not available for general download
  • Must run on the oldest still-supported Ubuntu LTS release (currently Ubuntu 14.04) without the installation of additional packages. Targeting the oldest still-supported LTS is to ensure that the AppImage will run not only on the very latest, but also on older target systems, such as enterprise distributions (not limited to Ubuntu)
  • Must execute in our Travis CI based testing environment
  • Must pass appdir-lint.sh
  • Must have a desktop file that passes desktop-file-validate
  • Must run without active Internet connection (and at least show some information)
  • Should have an AppStream metainfo file in usr/share/metainfo. If it does, must pass appstreamcli validation
  • Should show a useful screen rather than some crude dialog box since the main window will be used for the main screenshots. Note that you can provide your own screenshots by using an AppStream metainfo file
  • Should be available under a constant URL that does not contain the version number. Alternatively, should be available on GitHub Releases or the openSUSE Build Service (you are free to suggest additional serices like these)

Future catalogs

In the future, we may want to use decentral peer-to-peer databases for the catalog of AppImages.

We are currently investigating technologies such as IPFS and would be happy to win contributors in this area.