It's probably more accurate to say that Mozilla "uses" Netscape, depending on your definition of "use".
Mozilla is actually a "fork" of Netscape's browswer. Netscape released the source, and the open source community moved forward with it.
Mozilla is the result. There is a complete suite that is similar to the original netscape, and there are also beta versions of a new browser (Firefox) and email client (Thunderbird) available for download/evaluation.