TSL stands for Test Scripting Language. The test scripts are written in Test Scripting Language in winrunner. TSL is an enhanced, C-like programming language designed for testing. The advantages of TSL are: 1. It is easy to use. 2. It is similar to other programming languages. So a person who is in touch with basic concepts of programming can write test scripts easily. 3. It is a high level language. 4. The language provides various types of functions, which makes scripting easy.