Perl6 v. Perl5. Visual Basic .NET vs. VB6. ANSI C vs. K&R C.

Looking now, "Appendix A of the Fortran 77 standard lists 24 things that are not backward compatible in moving from f66 and f77."

Please tell me how the chasm between Python 2.7 and Python 3.3 is significantly broader than the chasm between the aforementioned languages.

I would go so far as to say VB.NET vs VB6 is the same as comparing any flavor of C++ to C#. It doesn't really make a lot of sense, even though they share the same pedigree.

VB.NET is effectively a different language entirely. It's programming .NET with VB-like syntax, not the VB language running on .NET (in my mind, anyways)

Ahh, but the goal is to find another language with "such a broad chasm between two versions of the language." It seems I can't win if people decided that my examples are so far apart that they are no longer two versions of the same language. ;)

What about Old S v.s New S? S v.s S4? S vs. R?

What about D1 and D2 of the D programming language?

Classic awk vs. nawk?

Honestly, I could go on. I think the person I'm responding to really doesn't know much about programming language histories.

Perl 5 and Perl 6 are completely different languages. The same can be said of VB and VB.NET.

There is a difference between a language rewrite and changing just enough of a language that it might have well been a rewrite.