As you know I've always been into Emulation in a big way.
A PC can emulate pretty much anything, and most emulators start out on Windows. Android has been seeing a bigger increase in Emulation support recently. And Linux has had a big upsurge in Emulation thanks mostly to Raspberry Pi, and now recently the retro handheld scene.
The Steam Deck is a unique device in this regard because it's running Steam OS, which is based on Linux, but designed to run Windows games and software using the Proton abstraction layer, and with Valve's hard work this is already working really well.
What this means is Steam Deck has access to both Linux and Windows Emulation. And using the packages now available you can add the emulators and each specific game directly into the main Steam frontend and navigate and run them like any Steam game. It will even sort your emulated games into collections based on each system, allow artwork etc to be included, and is still running the real emulsion in the background with all the configuration and setup options available.
The easiest starting point is one most will have heard of. Retroarch. A copy of this is even included in Steam for you to add to your liibrary and install. It auto sets up ready to go with a few cores already installed, and then launched take you to the faniliar properties screen to start setting it up. All the usual cores are also available in Steam directly, and all free.
But thr Steam version of Retroarch isn't the latest, so if you stick to that one for ease you are at the will of those managing that version to released updates.
Next we have EmuDeck. I've only just started looking into setting this up and having read and watched some videos this is looking like a brilliant solution. It installs and sets up standalone emulators and RetroArch, and even has EmuElec built in if you wanted to use that frontend over Steam. It's a massive project and undertaking.
To get an idea about EmuDeck take a look at this video.
https://youtu.be/AvzSHxccmIg
This video even showcases the hardware capability of thr Deck for Emulation. Running all RetroArch emulsion perfectly, and utilised for everything up to Dreamcast. For everything newer EmuDeck uses individual emulators. Right from PS1, PS2 and can even eun PS3 as well as the current emulators allow. It can also run Gamecube, Wii, WiiU and Switch perfectly well with a bit of tweaking. And can run Xbox and 360 games well too.
I'm going to be losing a lot of hours on this. It feels like I will be going down a massive rabbit hole with this, but it's one of the big rains I wanted a Steam Deck, alongside running PC games on a handheld. But as I've already setup other handhelds and emulsion frontends many times I have a lot already catalogued and sorted ready to use, so saves a lot of time and effort. Still a lot of work and I have a second 256GB SD card to dedicate to this ready to start.