What can we replace in the technology and remain in Ajax? If we replace JavaScript by another language, is it always Ajax?
The term Ajax is a set of standard techniques for creating dynamic pages, but it coexists with other techniques such as iframes and other technologies to exchange data with the server, and they are different things. A key aspect is the quality of being a standard. Replacing JavaScript with another language, would lose that status in Ajax. However, technologies that make up Ajax are evolving and thus it must evolve too.
The question is often asked whether Ajax can use another client-side language that JavaScript, therefore whether we are still in Ajax with another programming language.
As defined in the article by J.J. Garrett, Ajax relies on JavaScript, because it is standard and works on all browsers. There are other client side languages, but applications that use them do not have this quality, we can not talk about Ajax in this case.
Evolution of Ajax is in fact inevitable because Ajax is a combination of technologies that themselves are improved over times:
Ajax does not therefore designate something rigid, even if we stick to components originally described in the article by J. J. Garrett (see link below).
Ajax, a new approach to web applications The article that has coined the term Ajax and popularized its use.