Garry’s Mod 13 will be released on September 24th 2012. It’s going to be painful for those that haven’t prepared. This is a direct copy of the message to the world left by the creator:
Toybox is gone.
I know - we all loved toybox - it was great. But we’re moving to a Steam Workshop system now. I really believe it’s a better system for everyone. It doesn’t work the same as Toybox does. You install addons instead of using them on demand. Addons can be updated by their makers and are automatically downloaded and updated by all those that are subscribed.
Addons and Gamemodes will break
Sorry - but it’s inevitable. Certain systems in the code have been changed or removed completely and replaced with other systems. You can find a guide to what you need to change in your code here.
Most of the popular gamemodes have already switched. Make sure you ask the creator of your favourite gamemode if they’re GMod 13 compatible.
Not all bad
Starting in GMod13 I’m shipping my own engine.. which means I’m able to do loads of crazy crap that wasn’t possible before. This means fixes for some of the most common bugs - like the reliable snapshot overflow bug.
Get A Key Now
You can get a key for the GMod13 Beta now by logging into account.garrysmod.com and clicking the beta link.
Beta Keys are limited and new keys are added periodically - so if you miss out please try again.
Here are some links for further reading.