Open source software in general. Seeing Blender become an industry standard was awesome, and it looks like the Godot engine may do the same for gaming. Krita has evolved into a truly wonderful painting program (and not half bad as a Photoshop replacement), and Linux itself has come so far, having become a genuine gaming platform.
Quite happy about all of that. :)
If you're not sure what StopKillingGames is about, the creator of the campaign, Ross Scott (of Freeman's Mind fame) made this short video to give the rundown.