ADTPro 2.1.D2 is the DAN][ variant of ADTPro 2.1.0. The ADTPro disk image is adapted to support the Ethernet port of the DAN II controller card (Wiznet W5500 module).
ADTPro's default support for Uthernet/Uthernet II and LANceGS is dropped in this variant. This was necessary to make space for the DAN][ Ethernet driver instead.
Only the Apple II disk images differ to the official ADTPro 2.1.0 release (e.g. "ADTPRO-2.1.D2.dsk", "ADTPRO-2.1.D2.po"). The java-based host utility is unchanged.
With this ADTPro variant it is possible to use ADTPro's Ethernet support to upload or download volume and disk images from the Apple II to a remote PC. It is also possible to upload and download hard-drive volumes from the DAN ][ SD-cards itself - however, access to the DAN][ controller's SD cards is much faster and more convenient through its built-in FTP support. But ADTPro's Ethernet support is still really useful to access other volumes - those which are not stored on the DAN][ controller itself, but on external floppy drives etc.