We have GameMaker: Studio Professional free trials for all Global Game Jammers, thanks to YoYo Games!
Simply enter the code: GGJ-PW5Q2 into the voucher box of the YoYo Checkout to redeem your free trial that can be used within Studio Free to upgrade it to the Professional trial. The Studio Pro trial ends on March 1st 2016.
As well as the free trial of Studio Professional, YoYo are also offering 50% off Studio Pro, HTML5 module, and Android module for the duration of the Global Game Jam!
On top of that, have also launched the GameMaker Jam Jar, a central hub for everything you need to start out with GameMaker: Studio and Game Jams, including tutorials, assets and tools to help you with your jam entry!