If you have Steam on your PC you can get your copy of GameMaker by purchasing it on their store. However, if you have already bought GameMaker directly from GameMaker.io or elsewhere and want to link your account so you can use the Steam version without purchasing again (or you bought on Steam and now want to use the non-Steam version), then you can do that also.
This page will guide you through both options.
Purchasing GameMaker Via Steam
As with any product from Steam, it's simply a case of going to the Store, searching for GameMaker and then selecting the licence you want (information on the different licenses can be found here):
Once purchased, it will then be added to your Steam Library and clicking on it will install it. Once installed, you can click the Play button in the Steam Client to launch GameMaker.
On launch you will be prompted to sign in, which will require you to provide the username and password details for your YoYo Account.
IMPORTANT! When using GameMaker from the Steam Client, the client must be online. GameMaker will not permit you to login while Steam is in offline mode due to the way that Steam locks down on network communication.
All GameMaker Subscriptions are considered as DLC for GameMaker, so your Steam Library will only show 'GameMaker' but your purchased Subscription will be accessible through this Install.
Linking Your GameMaker Account To Your Steam Account
If you have already bought GameMaker from us directly, you can link your GamMaker Account with your Steam account and then use either/or of the versions (the Steam client version, or the standalone executable). To link accounts, follow our Help Article Linking Steam Account to your GameMaker Account
After you have followed the Help Article, you can now download GameMaker from Steam and use it from within the Steam Client.
The opposite is also true, and if you have bought a GameMaker licence on Steam, you can link the accounts and get the same licence applied to the stand alone executable of the product.