To give a brief example of 4D code, here’s an example. The following snippet will ask for a user’s name, then send it back to the screen 100 times in a modal dialog. Yeah, that’s annoying, but it’s just an example.

name:=Request(“What is your name?”)
for (i;1;100)
ALERT(name+” is the greatest!”)
end for

You will notice in the example above that a) semicolons are argument separators and b) All variables are implicitly typed. The standalone application supports full implicit typing, however if you compile your application you cannot coerce type changes (each symbol only has a single type within its scope), and you can set the compiler to require explicit typing if you choose.

In the case of PowerSchool they wrote their own web server and hand-coded all the pages, and it wasn’t AJAX based. I don’t work for Pearson, so I can’t tell you what they’re doing now.