Michal Parusinski

Counting the number of applications distributed as Snaps, Flatpaks or AppImages as a measure of the popularity of Linux universal packaging formats, let’s see how much existing Linux software has moved to Snap, Flatpak or AppImage. It should give us an idea of how successful these new packaging formats are with old open source projects.

Disclaimer: Now I must be honest: answering this question is difficult and easily subjective. I tried being impartial and accurate but you should take everything I state with a grain of salt. Try researching on your own.

Counting package format adoption

Because counting on my own whether each piece of software on Linux is available as a Snaps, as a Flatpak or as an AppImage is time-consuming, I decided to take a subset of popular Linux applications. To avoid putting personal bias in the list, I chose the set of software listed on FossMint. Because Google Drive and Evernote are not officially packaged for Linux, I have excluded them. This should give us a rough idea of the percentage of applications adopting universal packaging, and thus help evaluating the popularity of Linux universal packaging formats.

Using this list, I searched for the following:

• Are the projects officially adopting AppImage, Flatpak or Snaps as a means of distribution? In each case, I checked the project’s official website.
• Are AppImages, Flatpaks or Snaps available for the software in question, regardless whether the project official supports any of the format.
• Are AppImages, Flatpak or Snaps shipping the latest version?

Results

• About 14% of projects official distribute their software as AppImage, Flatpak or Snaps. Meaning that adoption is slow (the youngest of the three formats is 4 years old). Of the 14% (~10 applications) which moved to universal packaging, 40% (~4) have adopted Flatpak, 40% (~4) have adopted AppImage and 20% (~2) have adopted Snaps. However, because the sample of applications officially distributed as AppImages, Flatpaks and Snaps is so small, one should not conclude yet that Flatpak or AppImage is being more successful.
• Concerning whether software is being made available as Snaps, Flatpaks or AppImages, AppImage appears to be last with about 37%. Snaps and Flatpak are ahead with respectively about 46% and 47% adoption rates respectively. AppImage project’s insistence on upstream packaging explains this discrepancy. Overall, this means Snaps and Flatpaks are being more successful, but only because volunteers (not officially associated with open source software projects) package popular Linux software as Snaps and Flatpaks.
• Concerning whether we have the latest version packaged in each format, we see a big lead for Snaps. About 60% of Snaps provided ship the latest version, 53% of Flatpaks provided ship the latest version and only 37.5% of AppImages ship the latest version. Because probonopd, one of the main developers behind AppImage, created most AppImage bundles and has not been updating them for more than a year, the number of up-to-date AppImage bundles is fairly low. The numbers are healthier for Snaps and Flatpaks but it is still far from 100 percent. Many volunteers who originally packaged software as Snaps, Flatpaks or AppImages have stopped updating them, meaning a lot of the software is out of date.

Based on this list I don’t think one can claim Snaps is way ahead; if anything, it appears to be strongly in competition with Flatpak. One should not conclude AppImage is losing steam either, AppImage is doing well, with 634 applications distributed as AppImage according to AppImageHub and many developers choosing AppImage as the official format for Linux. A lot of software is distributed today as Snaps, as Flatpaks and as AppImages by enthusiasts, because projects are not officially adopting either formats. This means will still need to rely on maintainers to distribute and maintain software as Snaps, Flatpak or AppImages.

What’s holding back either Snaps, FlatPak or AppImage?

What stop developers from using Snaps, Flatpaks or AppImages? I searched various forums and GitHub for answers. Here are some of the main reasons:

• Lack of time, resources or motivation: This is one of the main reasons preventing a package format adoption. See for instance the following links: 1, 2, 3, 4. Hobbyists, who have limited time to work on their projects, are reluctant to learn or build for a new packaging format.
• Not even packaged: Many software projects are not even doing the packaging on Linux themselves. They assume maintainers will package for them.
• Software no longer developed: Lots of software are no longer maintained. For instance, Frozen Bubble was last updated in 2010 whilst Banshee was last updated in 2014. It is hard to expect projects with no developers to magically create a Snaps, Flatpaks or AppImages.
• Lack of agreement over which format to use: This is not frequent but fairly telling. How come there are 3 competing universal packaging formats? RStudio could not agree over which format to use.

Lots of people in the Linux community criticise Snaps, Flatpak and AppImage on technical grounds and disagree with the philosophy of universal packaging, but ironically this didn’t show up much as a reason not to support Snaps, Flatpak or AppImage. I think the people complaining about universal packaging are usually not software developers; the criticism comes more from system administrators, Linux distribution developers/maintainers and users who choose Linux for its security.

Conclusion

Overall, traditional Linux software appears reluctant to adopt Snap/Flatpak/AppImage. So, in terms of the popularity of Linux universal packaging formats, I’d say it is still fair game.