[jarcane]

Sadly the ECMA standard for BASIC never really got adopted by anyone (and is now pretty outdated style anyway).

MS Basic kiiinda became as close to a defacto standard as can be described, just because it was the most common and commonly imitated.

In terms of a modern standard, there's quite a few modern BASICs, but the same kind of applies: Microsoft kinda leads the field. Many of the surviving projects are either directly or indirectly based off of QuickBasic and Visual Basic, or at least heavily inspired by them.