In the very center of the .NET platform beats its heart – the Common Language Runtime (CLR) – the environment that controls the execution of the managed code (MSIL code). It ensures the execution of .NET programs on different hardware platforms and operating systems.

CLR is an abstract computing machine (virtual machine). Similarly to physical computers, it supports a set of instructions, registries, memory access and input-output operations. CLR ensures a controlled execution of the .NET programs using the full capabilities of the processor and the operating system. CLR also carries out the managed access to the memory and the other resources of the computer, while adhering to the access rules set when the program is executed.

The .NET Platform