The Nintendo DS Web Browser is a version of the Opera web browser for use on the Nintendo DS, developed by Opera Software and Nintendo. The Nintendo DS Browser comes in a version for both the Nintendo DS and the Nintendo DS Lite. This is due to the physical size differences in the memory expansion cartridges used by the browser (Game Boy Advance sized cartridges do not sit flush within the Nintendo DS Lite). It was released first in Japan on July 24, 2006, and in Europe on October 6 2006. The North American release date is not announced; however, an Opera spokeswoman has confirmed that the browser's next stop will be the US, although no timelines were disclosed.