Dear NAV developers,
Navision has been around since the 1980'ies and even today there are customers still using the DOS based versions.
Developers who work directly at a user, typically work with just a single version. If you work at a partner, then you may work with many different versions.
The questions here in the Developer Forum already shows a wide variation in versions, but which versions do you use the most?
If you like to read more about the many different versions of Navision, check out the Wiki here on DUG: