Unity3D game engine
Introduction to Unity3D
Unity3D Engine is currently the most popular game engine in the world. It is suited both for 2d and 3d game and simulator development (but also applications, systems, websites and recently also VR).
A great feature of Unity3D is one code base for multiplatform exports - it means, that a single code of a game or application can be used to create builds on many platforms, such as:
Unity also has a great built-in editor, in which even a person who is not familiar with programming can participate in the development of the project, e.g. by placing objects on the scene and testing it in the runtime. A great feature of the editor is that you do not have to pause the game in order to check how a change on the scene influences the gameplay - all changes are visible in the emulated game window instantly!
In Unity, development can be done in several programming languages:
Comparing to other engines
There are other engines on the market, such as Unreal Engine or Cry Engine, which supposedly offer similar features, however this is not entirely true. A flag example, which puts Unity ahead of its competitors is the mobile build size. The smallest Android game build made with Unity is 6.5 MB. A smallest Android game build made with Unreal Engine 4 is 28 MB. This is a significant difference, as the optimization is kept on a similar level*
(*even with slight advantage towards Unity).
Unity is a great tool, which stands stable on the top of the league and the business situation of the Unity Technologies suggests, that it will remain this way - as more and more investments are made into developing this marvelous tool.