One of the best things about GOG is that you don't have to mess around with bloated, resource-sucking launchers to get and play your games: You can just go to the website, download, install, and run—just like the good old days, which of course is the foundation upon which GOG is built. ("Good Old Games," remember?)
For those who do like launchers, though, and to reflect the fact that it also carries some new games, GOG unveiled the Steam-like Galaxy launcher earlier this year. It offers the usual features, like library views, a friends list, and in-game activity logs, but the big hook is that it pulls all the games from other launchers—Steam, Origin, Battle.net, EGS, Uplay—under one roof. As James explained in June, those launchers still have to be installed, but Galaxy can make them effectively invisible—and it does a really good job of it.
Galaxy has been in closed beta for several months, but now it's available to everyone in open beta. Along with pulling all your various game libraries together in one place, the open beta release also adds support for cross-platform friends lists and stats—things like what games people are playing, achievements they've earned, and hours they've sunk into the effort. Galaxy doesn't support every single feature offered by other clients—the Steam friends list integration doesn't support built-in chat, for instance, so you'll still need to rely on the Steam client for that—but overall it seems quite robust.
It's also very simple to use. Start the client, hit the "settings" dropdown, select "add games and friends," and then "connect platforms." Each one will prompt you for the usual login stuff, after which your libraries and activity will be imported and maintained automatically. Each game has its own page listing activity, achievements, playtime, and editable details like title, release date, tags, and images.
I haven't played with it much, but what I've seen looks really good. When I launched Dusk, for instance, the only indication that Steam was involved in the process was a small popup notification that a Steam game was launching. That said, there also appears to be a few rough edges: The Outer Worlds, for instance, which I own through the Epic Games Store, isn't appearing in my library. There might be a simple fix, but I gave it the ol' two-minute try and got nowhere, so I'm moving on for now. Hey, open beta is still beta.
Minor bumps aside, GOG Galaxy looks very solid at this point, especially if you're looking to cut back on multi-storefront clutter. (And who isn't?) Give it a try at gogalaxy.com.