The development of commercial business software is the main purpose behind the designing of the fourth-generation programming language. It is nothing but a programming language that can be simply abbreviated as 4GL. It is true that abstraction moved a step higher with the introduction of 4GL in the history of computer science. It was quite natural that 5GL simply followed 4GL in abstracting the language further.
Experts in the field of computer science felt that 3GL had certain shortcomings including slow development methods and liability to errors. Hence the necessity of 4GL arose. A need for the introduction of a higher-level programming language was clearly felt by them. The new programming language would be in a position to simplify the complex 3GL instructions and would be effective in minimizing errors too in the process. Thus it is understood that 4GL and 5GL are looked upon as error minimizing programming languages. All projects involving 4GL are also considered systems engineering-oriented.
There are several advantages of using 4GL. They are in fact designed in such a way that they are capable of lessening programming effort and minimizing the time taken to develop software. They are adept in controlling the cost of software development too. It is a common practice to compare fourth-generation languages to domain-specific programming languages or DSLs. Experts also consider that 4GLs are a subset of DSLs.
It is important to note that there are several types of 4GLs. Some of them are the table-driven programming that runs with a runtime framework and libraries, report-generator programming languages that record the description of the data format and data management 4GLs that supply complicated coding commands for manipulating data.
Some fourth-generation languages include Clipper, Cucumber, DataFlex, FoxPro, Genero, Progress 4GL, Ingres 4GL, Quest, Report Builder, Oracle Reports, CorVision, FOCUS, LANSA, LabView, Nomad, GraphTalk, Stata, UNIFACE, eDeveloper, Sculptor 4GL, Omnis Studio, AMPL, ColdFusion and GAMS.