Which AppImage should I install (.AppImage vs modern.AppImage)?

Question

I'm installing the Ultimaker Cura 3D printer slicer program from here (https://github.com/Ultimaker/Cura/releases/tag/5.1.0) onto Linux Ubuntu 20.04.

1. What is the difference between Ultimaker-Cura-5.1.0-linux-modern.AppImage and Ultimaker-Cura-5.1.0-linux.AppImage? Which should I use? Why? How do they differ?

I've posted this on their forum too.

Update: important installation reminder to myself and others:

After downloading the desired AppImage for your operating system, per the accepted answer below, be sure to make it executable as well! Then, you can double-click on it in a file browser to run it.

Ex: how to install Cura on Linux Ubuntu 20.04:

# download it
wget https://github.com/Ultimaker/Cura/releases/download/5.3.0/UltiMaker-Cura-5.3.0-linux.AppImage

# Make it executable
chmod +x UltiMaker-Cura-5.3.0-linux.AppImage

# Now run it. 
# Option 1: double-click the file in a GUI file manager
# Option 2: run it from the command-line:
./UltiMaker-Cura-5.3.0-linux.AppImage    # run in foreground
./UltiMaker-Cura-5.3.0-linux.AppImage &  # run in background

Related:

1. My question: How do I check or verify a pgp/gpg signature using a .asc PGP signature file?

Answer 1

According to the cura-installer.yml file they are both the same AppImage, however one is built using Ubuntu 20.04 and the other is built using Ubuntu 22.04:

include:
    - { os: macos-11, os_id: 'mac' }
    - { os: windows-2022, os_id: 'win64' }
    - { os: ubuntu-20.04, os_id: 'linux' }
    - { os: ubuntu-22.04, os_id: 'linux-modern' } # <==========

You can search the repo for all of the latest mentions of linux-modern here: https://github.com/Ultimaker/Cura/search?q=linux-modern

Even though it's an AppImage, this is very commonly done to prevent problems from ABI changes of glibc and other libraries. I would recommend running the normal AppImage, as building on the oldest LTS is very common for most software; Cura providing a “modern” build is a big exception to the norm. And only run the “modern” build if you have difficulties with that.

Answer 2

Try modern first, and if that doesn't work then use the other one.

Debian 11 / Devuan Chimera fails to run the Modern file with this error which harms nothing:

[29776] Error loading Python lib '/tmp/.mount_Ultimae7Etxc/libpython3.10.so.1.0': dlopen:
/lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.35' not found (required by
/tmp/.mount_Ultimae7Etxc/libpython3.10.so.1.0)

But the other appimage file runs perfectly.