Software
Linux tools -
at51tool-0.9.4
Firmware
Atmel's AT89C52/S52 -
at51fsc-0.0.5
Hardware
PCBs for AT51Programmer -
at51hw-1.0.0
PCB AT51MAIN -
at51main-1.0.0
PCB AT51PR51 -
at51pr51-1.0.0
Both PCBs (AT51MAIN and AT51PR51) are included in at51hw
Manual and documentation
Manual -
at51doc-0.0.3 (obsolete)