Applications-By-Forms (ABF) is an early 4GL computer programming language provided by the Ingres relational database. It provides an ASCII form painter, which automatically binds form fields to a database using ABF, a programming language, with embedded SQL, simplifying the task of making a "CRUD" application for textual data.
ABF source code is interpreted into a 3GL language (C or COBOL), which is then compiled so snippets of the native language may be directly embedded in the ABF code.
ABF was deprecated by OpenROAD in the early nineties.
Several other database vendors marketed comparable 4GLs at around the same time, such as Pick System Builder, Clipper, and DBASE III.
References
Applications-By-Forms Wikipedia(Text) CC BY-SA