It depends on bank and which technologies(like java or .net etc) they are using to build there application.

Depends on technologies and the application will also be different based on bank's business process.

Now I see what you are saying. Like in nepal bank using (Pumari )one software, but I think in US every Bank have there own application which is based on there business process. ( on requirement ). ( I nepal bank can not spend hugh amount to build so they buy software) not sure but that is my view.


Lets take on eg.-  if u see citi bank url -- https://online.citibank.com/US/JPS/portal/Index.do this is Java/JSP using struts frame work. (Correct me if I am worng Java experts )

I hope this helps.