I've already talked about this here:

https://forums.dolphin-emu.org/Thread-dolphin-as-appimage-on-linux

What is an AppImage?¶

http://appimage.org/
To quote the website:

"As a user, I want to download an application from the original author, and run it on my Linux desktop system just like I would do with a Windows or Mac application."¶

"As an application author, I want to provide packages for Linux desktop systems, without the need to get it 'into' a distribution and without having to build for gazillions of different distributions."¶

Using AppImages solves the problems with distributing development versions for multiple Distributions once and for all.

You simply download a file, make it executable, and it runs. No need to fiddle with compiling Dolphin, third party repositories, nada.

I've looked at Flatpak and Snappy, but it seems those don't allow direct udev access (like Dolphin needs for controllers to work), and the NVIDIA driver isn't playing along very well with either of those. (It does partially, where they include their own libGL inside the package, but newer drivers/devices are completely ignored when doing that.)

I've already created some AppImages for Dolphin, including a build script. Run those in Ubuntu >= 16.04 as much as you want, the newest version should also work on the latest Fedora release.

See here: https://drive.google.com/open?id=0B-tFnZC4LvDuXzBuM0Q2V2hSdTA

Issues and general problems with this idea:

• No expert in bash, the script I wrote isn't very good
• Running Dolphin in english gives a warning about the language catalogue being invalid.
• Dolphin isn't relocatable once compiled, so the binary needs to be patched to simply look at "././" instead of /usr. This might be solved by compiling it with a "././" prefix, but I haven't tried that yet.
• AppImage is becoming bigger with distros getting newer libraries. Right now it's at 27MB
• Not all distros should get official support. Main points should be Ubuntu and Fedora. People on Arch can probably fix it themselves.
• Currently requires Ubuntu 16.04 or later. I can't find a way to compile it with Vulkan support on 14.04.