GNOME 3.10 is about to be released with the new gnome-software, a "Software Center" for the GNOME environment.

gnome-software is designed to be a pluggable architecture, so that it could install software from various sources and not only the distro's package management system.

This is where Steam comes to mind: it would be awesome to have a Steam plugin for gnome-software that will allow us to show available Steam games for the users (provided they have Steam, and the plugin, installed on their systems) to install or purchase, and will show installed Steam games to allow users to easily remove them (just like Steam games on Windows register themselves in Add/Remove programs).

Some implementation detail - what is needed from Steam if you want to support this:

• clicking install (or purchase) will pop up the Steam client via steam:// url handlers
• Steam should install desktop files automatically for all Steam games currently installed. If you don't want the users to see them in the menu, you can add OnlyShowIn=Steam or something similar so desktop environment won't show these desktop files. This is required so we can detect what Steam games the user has installed. These desktop files should also contain an extra field with the game's Steam appid.
• Need some sort of API to trigger Steam app removal. Steam client should probably ask user for confirmation if this is implemented.
• We need an API to detect which games the user owns, so we can change the button text from "Buy" to "install" (we could use Steam Web API's "GetOwnedGames" method, but we'd need to somehow know the user's steam ID for that, can the steam client provide it to the system somehow? a d-bus service that will allow us to ask the steam client for the id of the currently logged in user might be a good idea)
• We can fetch app descriptions from the web by scraping steamdb.info or by using the same APIs SteamKit uses, unless you do this for us and are willing to generate appdata files for us to read from.

Benefits of implementing gnome-software support:

• Users will be able to remove and install steam apps just like they remove or install distro-provided apps (and soon Firefox webapps and more types of apps!)
• Steam would feel more integrated with the rest of the system
• gnome-software's easy to navigate category view might be easier for users than the Steam Store interface
• we could probably make the plugin show Steam games in the Featured section of gnome-software, gaining more exposure
• Everyone would love you for being awesome
• Apps or games that originate from steam will feel more like first-class-citizens in the GNOME environment

So, what do you say, will you help us do this? It seems that most of what we need is already in-place, and only few changes are required on your side.

(CC @hughsie, gnome-software maintainer)