Distro-agnostic emulator packages for Linux
Distro-agnostic packages are application portability solutions in Linux.
There are thousands of different distributions of Linux, and many of these use different package systems to manage application installation. Some popular ones are .deb format used by Debian, Ubuntu and its variants, and there is also RPM format used by Fedora, RedHat, and many others. Packages of game console and computer emulators exist for popular Linux distros, usually available from the official software repositories of the distribution, but they are usually very old compared to the upstream versions. In addition, these packages are typically made only for one single version of the distribution, and due to dependency problems these can not be used in other distros. There are at least three new package formats that are aiming to bring application portability to the Linux ecosystem. Packages using these formats are quite huge in file size due to bundling all dependencies in it, but they can run in any popular Linux distros.
Flatpak (formerly xdg-app) is a distro-agnostic application framework. It is a decentralized system and has no central package repository. Instead, the user must manually add the repository's URL to the system before packages can be installed, like in Ubuntu's PPA.
Flathub, probably the biggest Flatpak repository, has the following emulators:
Snappy, also called 'snaps' or just 'snap', is a distro-agnostic application framework made by Canonical, the Ubuntu devs. Unlike other formats, it is a centralized system and has the official repository to download the packages from.
Snappy has the following emulators:
- RetroArch (Official Announcement)
- Hatari 
- DOSBox 
- FS-UAE 
- Atari800 
- VICE 
- ScummVM 
- Virtual Jaguar 
AppImage is a package format that allows software distribution without a superuser permission. Unlike the other two, AppImage does not have a system to find, download, install and uninstall the packages. Instead, it works like Microsoft Windows exe files with no DLL requirements. The user must give the 'execuable' permission to the AppImage package (chmod +x ./appname.AppImage) but this is the only requirement.
Unfortunately, emulator adaption is very poor compared to other two systems. RPCS3 is the most notable emulator to officially adapt this format, but aside of unofficial build of RetroArch and Dolphin (both are outdated compared to upstream releases) no other emulators are known to available in this format.
List of AppImage packages can be found in AppImageHub, but as of December 11, 2017, this site does not list RPCS3 or any other emulators in it.