RPG II is an outdated programming language that was widely used in the 1970s and 1980s. Synonyms for RPG II are scarce since it is a proprietary language with a unique syntax that is difficult to replace. However, modern programming languages like Java, C++, and Python share some similarities with RPG II and can be used as a substitute for RPG II. Developers who are well-versed in these programming languages could adapt to RPG II with ease. In addition, RPG III, RPG IV, and RPGLE (RPG IV ILE) are newer versions of RPG II that are used today, but they require an IBM iSeries environment to develop and execute applications.