Development tool provider Digini said that it will stop support for its subscription-based development engine Blade3D in six months -- and competing engine developer Unity is swooping in with a discount offer for Blade3D customers who were "left out in the cold."

Blade Games CEO Tom Sperry said in a forum post in late July, "We have decided to wind down Blade3D in its current form as a 3D game engine and leverage the technology in a new direction."

Sperry did not reveal the specifics of that new direction. Current subscribers will get the next six months' use of Blade3D free of charge. The engine was available at a monthly rate from between $14.95 (for hobbyists) to $99.95 (for game companies, per seat).

Blade3D customers posting in the Digini forums were discouraged by the news. "I don't know what to think, someone has just pulled the development platform I chose from under my feet," said one user. "So... I've got months of tools as-is to use for free. ... But really now I've got to find something else if I want to develop a game."

Another poster wrote, "A shame really. It was a good engine, but without the source and a subscription based license, I see my fears have come to fruition, much sooner than I had expected."

Competing engine developer Unity saw the Blade3D shutdown as an opportunity to gain more customers for its own tools. In a Friday post on Unity's official blog, CEO David Helgason said Unity would "[credit] subscription fees a Blade3D customer has paid towards any Unity license, up to 50 percent off its full price."

He added, "Since Blade3D used C# for scripting just like Unity can, anyone well versed in Blade3D will be right at home in Unity."

Helgason said the Unity user community stands at around 10,000 developers. The company's engine supports PC, Mac, iPhone and Wii.