Ad hoc group called the Holocene Impact Working Group (HIWG) was created as follow-up the Workshop on Comets/Asteroid Hazard that was held in the Canary Islands in December of 2004. The group includes the researchers from different field of geoscience who believed that Holocene comet impacts were more frequent in the recent past than the accepted view. The part of this web-site is not open to a wider audience and contains documents and data currently circulating between group members.