AppImage

What is an AppImage
 'Package once and run everywhere. Reach users on all major Linux desktop distributions.' 

AppImage is a "universal binary package" intended to distribute an application to any Linux distribution. Read more about it on the Appimage homepage and Wikipedia.

For other types of installation see Download.

Stable version
Current stable version is FreeCAD_ (SHA256)

Development version
Current devel version is FreeCAD_ (SHA256)

Important Notes:
 * Development happens daily and rapidly, the link for the most up-to-date AppImage is a moving target.
 * The development link above should be up-to-date because it is updated via a script.
 * Many users on the forum utilize the development version.
 * It can be run on the same system in parallel with another version of FreeCAD.
 * Users use the dev version to take advantage of the latest features and bug fixes (since FreeCAD has a long release cycle). They also use it to help test and find bugs to spur development and improvement of FreeCAD.

Obligatory Word of Caution
For the most part the development version is stable but of course it's important to add the obligatory statement to use it at your own risk. Though most people that utilize backups and 'save often' do quite well.

Automatic updating
AppImage has a smart and economical way of updating. It calculates the difference between the new AppImage and the old one, and will only download the changes between their versions. In theory the user ends up downloading around 15% each time instead of an entirely new AppImage.

Automatic updating is done via several optional methods. Currently there are 4 methods, 2 through the graphical interface (GUI), and 2 through the command-line/terminal interface (CLI).

GUI method 1 (official)
This is the official AppImageUpdate GUI application.
 * 1) Download AppImageUpdate-x86_64.AppImage.
 * 2) Make it executable by right clicking on the file, going in to properties and "Run as an executable".
 * 3) Double click on the AppImage icon, a dialog box will appear and you'll be prompted to specify what AppImage you want to update.
 * 4) Specify the path to your existing AppImage.
 * 5) Once the AppImage is updated, press the button.

GUI method 2 (unofficial)
This is a sleeker 3rd-party unofficial version of AppImageUpdate named: AppImageUpdater. It is still in development (at the time of this wiki edit) but nevertheless, quite nice to use. Result: Follow the AppImageUpdater prompts
 * 1) Download AppImageUpdater-*-x86_64.AppImage
 * 2) Make it executable:
 * 3) Run it:
 * 4) Find your current FreeCAD AppImage and drag-drop it on to the AppImageUpdater

CLI method 1 (official)
Run the following instructions in your terminal

Notes:
 * The file names will be unique because of the version info is embedded in them. The above instructions are simplified for convenience.
 * Run to learn about functionality like  and.
 * There is also an i386 version; see the AppImageUpdate release page.

Todo: share a script that can be added as an alias or cron job.

CLI method 2 (unofficial)
Similarly to the Graphical methods having an official and unofficial approaches to downloading AppImages, the same applies to the command line. This is a sleeker 3rd-party command line option to download AppImages

Result: Updates specified AppImage file if update exists
 * 1) Download appimageupdater-*-x86_64.AppImage
 * 2) Make it executable:
 * 3) Run it:

Unpacking AppImages
this section is intended for developers.

A very convenient aspect of FreeCAD is that a majority of it is built in Python, which doesn't need to be manually compiled like C++. Essentially, a Python file can be modified, and upon restarting FreeCAD those changes will be integrated into the application. A developer can quickly work on the latest FreeCAD release using this technique and an AppImage. Moreover, using an AppImage doesn't modify your system's environment in any way, that is, nothing is installed and no environmental variables are modified.

Modifying AppImages
An AppImage embeds a file system in it with everything that is required to run the application. In order to modify it, the file system needs to be extracted.

Now open the required Python source files in your preferred code editor, modify them, and save them. Then run the application.

Repackaging AppImages
If you've modified the code, and now want to re-package the AppImage with your latest changes, use the appimagetool-x86_64 tool on the extracted file system.