3GLs

Third-generation languages (3GLs) are high-level programming languages developed during the 1950s and 1960s intended to be more abstract from the processor than assembly language. They are designed to express algorithms and data structures in a syntax closer to human language and mathematical notation, rather than machine instructions. 3GLs are typically compiled to machine code or translated by an interpreter, enabling greater portability across hardware and more productive software development compared with earlier generations.

Characteristics include support for procedural or object-oriented paradigms, structured control flow, and the use of meaningful data types and abstractions such as arrays and records. They generally require a compiler or interpreter and encapsulate complex operations behind higher-level language constructs, enabling programmers to implement complex systems with less code.

Common examples: Fortran and COBOL are among the earliest 3GLs; later 3GLs include C, C++, Pascal, Ada, BASIC, Lisp, and Java. These languages have been used in scientific computing, business processing, systems software, and education. Their influence extends to modern languages, many of which are direct descendants or hybrids that emphasize high-level abstractions and portability.

Impact and evolution: 3GLs reduced the need for hand-coding in assembly language, enabling larger programs and more maintainable software. They paved the way for later generations (4GLs and 5GLs) that further emphasize productivity, domain-specific languages, and declarative or AI-oriented programming. The exact categorization of languages can vary by source, but the term 3GL generally encompasses high-level languages that require translation to machine code.