Conditional compilation

Template:Distinguish2 In computer programming, conditional compilation refers to methods which allow the compiler to produce slight differences in a program depending on parameters that are provided during compilation. This technique is commonly used when these differences are needed to run the software on different platforms, or with different versions of required libraries or hardware.

Many programming languages support various methods of doing this. For example, in C, and some languages with a similar syntax, this is done using an '#ifdef' directive.