Masthead Studios is a Bulgarian game development company, founded in 2005. In addition to developing and operating its defunct post-apocalyptic MMORPG Earthrise, it also was involved in co-developing Interplay's original Project V13.
On April 2, 2009 Interplay announced a binding letter of intent with Masthead Studios to fund the development of Project V13 (Fallout Online). Masthead and Interplay teams will work together under the direction and control of Interplay to complete development of the project.  Up to 35 Employees were assigned to the project with work ceasing in May 2011.
This game had been developed up to the point where it was playable, although admittedly using some Earthrise assets. Masthead also created some assets for the game based on mutated animals and Californian landscapes.
Production was suspended during the Bethesda Softworks LLC v. Interplay Entertainment Corporation court case.
Following the relaunch of Black Isle, a new Project V13 was announced to build a prototype game engine for a Strategy based RPG. It was confirmed follwing this that previous work had been abanoned in favor of a new direction. Masthead have no apparent involvement in this project.
Masthead's current projects include a sequel to Earthrise subtitled "First Impact", a free online shooter called "Guns and Robots", and an IOS game titled "Jelly Tunes".