Simple Program Language (SPL) is a type of programming language that is designed to be easy to learn and use. It is often used as an introductory language for those new to programming, as it is relatively straightforward and does not require a lot of technical knowledge. The most popular SPL is BASIC, which stands for Beginner's All-purpose Symbolic Instruction Code. BASIC was developed in the 1960s and has since been used in many different applications, from educational software to commercial software. It is still widely used today, and is considered one of the most influential programming languages of all time.