The TANPAKU home page roughly translates to:

Dear all of TANPAKU volunteers,



TANPAKU server has been down from August 18th accidentally. Now we are repairing the server. We are sorry for the inconvenience caused.



TANPAKU staff

TANPAKU to everyone for participating Monday, August 18, but the server is stopped suddenly, and are currently working to recover. Everyone has become to the inconvenience, We're sorry.



Staff TANPAKU


I realise August was a long way back but I don't think it has been officially confirmed dead yet. However, if this is reason enough to archive then Rieselsieve (BOINC) should be archived too.