Any program that implements the LDraw.org File Format is considered "LDraw compatible". This is a little bit fungible since we don't really enforce this in any way (nor could we).
As for the LDraw name, we don't have any control. We are graciously allowed to use the name by the estate of James Jessiman. That said, as long as your program/converter/whatever has something to do with LDraw and you are not passing yourself off as officially endorsed by LDraw.org then you'll probably be fine.
As for the LDraw name, we don't have any control. We are graciously allowed to use the name by the estate of James Jessiman. That said, as long as your program/converter/whatever has something to do with LDraw and you are not passing yourself off as officially endorsed by LDraw.org then you'll probably be fine.