Is it possible to get Steam keys to the games I own on GOG, and GOG keys to the games I own on Steam, without repurchasing them? I know the chances are quite small, but on the off chance that one of my profiles became corrupted, (as happened to a friend of mine), I'd feel safer knowing that my games were backed up on my other game client. Besides, as there is a lot of overlap in game libraries, it can be irritating to log into both in order to figure out on which client I own the particular game I'd like to download. (I know this is a total First World Problem.) Thank you!

Hello,
I too have wanted to do this a while back, but you simply cannot. There was however an exception, the Witcher series. If you bought the game on Steam, you would also receive a GOG key.

Which friend's profile become corrupted?

0.0.01%

A very small number of GOG games activate on Steam either directly (e.g. Arma 2) or by registering the included key on the developer's site to generate a Steam key (e.g. Race the Sun).

Steam games don't activate on GOG apart from The Witcher games (as has already been mentioned).

Well you could always ask the developers/publishers of the games. They are the ones who, as I understand, can get Steam keys for free.

Anyway, corrupted profile is less of a problem with GOG. Since it's DRM Free you can download and backup all you game installers and no matter what happens to GOG you will always be able to play your games.

Personally I have a external hard disk on which I backup all my GOGs and extras. It's USB 3.0 so it's also very fast and easy to backup.

i do that as well, mine is a 2TB WD passport & even with all the GOG's, extras & mods stored, there is a lot of space left

Also, if your profile were to get corrupted, GoG customer support is very good. It might time them a few days at times, but they really do look into the detail of any given situation.

I know that gog and Steam are kind of competitors, so I understand that the initial request may not be feasible.

However, a slightly different request, which I'd like to hope is more feasible for gog:

Being able to sync your steam account with gog, so that gog would know that you own specific games. This way, in situations with a group of games being in a combined sale, those games would not count. Or in a situation where random sales (like the luck of the irish draw thing a while back), the owned steam games would not appear. Or if there is some official personalised giveaway, those games would be excluded for that user.

Could also include some sort of setting to turn that off, or allow for specific games and so on.

...please? :D

EDIT: To clarify, you wouldn't be able to download the gog versions of your steam games, but it would know that you own those games already.

Hmm GOG Galaxy is supposedly including cross platform Galaxy/Steam multiplayer and if Galaxy can hook into Steam for that I wonder what else might be possible - like maybe launching your Steam and GOG games from one Client (or Galaxy invoking the Steam client when it needs to anyway)
May have the purists up in arms again though...

Not sure if its because I initially installed my Steam version but when I start Burnout Paradise from Origin (for the cloud saves) it invokes Steam to launch the game so this sort of thing DOES appear to be possible - I DID have to activate both my Origin and Steam Burnout Paradise keys though, admittedly!