After a year or so of being available for a modest monthly subscription fee, Epic Games has now made its premium game engine and development toolset, Unreal Engine 4, available for free. For everyone. No strings attached. Well, maybe just the one.

The Unreal Engine is a pretty big deal for gaming, so much so that many high-profile releases from the last decade or so bear the infamous logo during their boot sequences. It even got to the point where just looking at a game you could tell if it was running on the Unreal Engine or not. Unreal Engine 4 is the latest version of the engine, which has been specifically designed to take advantage of modern graphics hardware and console technology.

Speaking of nerds, Epic Games founder Tim Sweeney announced the news of the engine going free today on the Epic Games Unreal Engine Blog (the EGUEB). So what's the catch? Why would one of the industry's most technically impressive development engines that has been used to power some of the biggest games be made available, for free, to every Joe Shmoe of Shmoesville? Well, according to Tim Sweeney it's all about revenue sharing after success.

When you ship a game or application, you pay a 5% royalty on gross revenue after the first $3,000 per product, per quarter. It’s a simple arrangement in which we succeed only when you succeed.

So, pretty simple. And it makes a lot of sense, especially when non-profit organisations and educational institutes can now use the toolset for the new low, low price of $0.00.

Check out the video announcement from Epic Games below.