AXCAD's native file format is dwg, AXCAD can open and save AutoCAD dwg file from version 2.6 to the current 2008, No worry about lost dwg data, No worry about your partners can't open your file too, AXCAD use dwg file only.
AXCAD provides high degree of compatibility with industry standard autocad command set. Axcad won't change the behavior how you drafting. Everything is familiar to you, it won't take you much on learning how to use AXCAD.