Mojang 2012, Mojang was co-developing a video game codenamed "Rex Kwon Do" alongside an undisclosed developer. Before the title had reached a significant stage of development, Mojang cancelled the collaboration, due to their lack of involvement and influence on the project. In March 2012, Persson revealed that he would be designing a space sandbox game. Although Mojang teased with an April Fools' Day website based around "Mars Effect" (citing the Bethesda lawsuit), it was confirmed that the game was indeed in development, albeit with a different name. On 4 April, Mojang revealed the game's title to be "0x10", set in the
Minecraft just built a game. He's tricked 40 million people into learning to use a CAD program." Various software has been developed to allow virtual designs to be printed using professional 3D printers or personal printers such as MakerBot and RepRap. In September 2012, Mojang began the "Block By Block" project in cooperation with UN Habitat to create real-world environments in "Minecraft". The project allows young people who live in those environments to participate in designing the changes they would like to see. Using "Minecraft", the community has helped reconstruct the areas of concern, and citizens are invited to enter the