In this paper we describe RTX, a framework for development of real-time applications on embedded systems. RTX facilitates programming and structuring of source code when building this kind of applications. Also, RTX seeks to improve user-computer interaction in real-time applications development and helps to exploit the capabilities of multicore processors in modern embedded systems. In addition, RTX allows the programmer to build and execute real-time applications from a Graphical User Interface (GUI) inspired in the Arduino environment, in the same way, an Application Programming Interface (API) is provided through a functions library for the C ++ programming language. For RTX validation, a real-time concurrent control system was implemented on a Raspberry Pi board by using designed API and GUI.