Later writers have somewhat redefined the meanings as distinctions previously seen as important became less significant to current practice.
[2][3][4] Examples: C, C++, Java, Python, PHP, Perl, C#, BASIC, Pascal, Fortran, ALGOL, COBOL 3GLs are much more machine-independent (portable) and more programmer-friendly.
This includes features like improved support for aggregate data types and expressing concepts in a way that favors the programmer, not the computer.
First introduced in the late 1950s, Fortran, ALGOL, and COBOL are examples of early 3GLs.
Examples: ABAP, Unix shell, SQL, PL/SQL, Oracle Reports, R, Halide Fourth-generation languages tend to be specialized toward very specific programming domains.
OPS5 and Mercury are examples of fifth-generation languages,[10] as is ICAD, which was built upon Lisp.