CODESYS^® is an independent development environment for programming controller applications according to the IEC 61131-3 industrial programming standard. It is the basis of a comprehensive suite that covers the entire software side of automation. Modern editors, debugging functions, and integrated compilers allow for an easy handling of all engineering tasks. The CODESYS Development System can easily be extended to suit individual requirements. In order to be able to execute automation applications, the CODESYS Control runtime system must be ported to the target device by the means of toolkits. With the integrated visualization, users can create and animate professional user interfaces for testing, commissioning, and servicing machines and plants. Different visualization runtime clients are available.

In addition to standard technologies such as FDT, CODESYS supports all standard fieldbus systems, such as Profibus, CAN, ModBus, EtherCAT, Profinet, or EtherNET/IP with integrated implementations, and partly with protocol stacks as portable CODESYS libraries. Field-tested motion control components make the IEC 61131-3 programming system a complete solution for motion tasks. A CAM, a 3D CNC/DIN66025, and a platform-independent library POUs for axis control are included. CODESYS Safety SIL2 and SIL3 are integrated safety products that have been IEC 61508 certified by the TÜV. All Safety products consist of Safety components in the runtime and programming system.

CODESYS is a target for the output of Simulink PLC Coder™ from MathWorks. This means that simulated models and architectures can be converted into IEC 61131-3 code (ST structured text). This code can be included in PLC application software and is then linked and compiled for automation systems. PLC Coder supports both available CODESYS versions: CODESYS V3 and CODESYS V2.3.