  Much of work in semantic web relying on Wikipedia as the main source of
knowledge often work on static snapshots of the dataset. The full history of
Wikipedia revisions, while contains much more useful information, is still
difficult to access due to its exceptional volume. To enable further research
on this collection, we developed a tool, named Hedera, that efficiently
extracts semantic information from Wikipedia revision history datasets. Hedera
exploits Map-Reduce paradigm to achieve rapid extraction, it is able to handle
one entire Wikipedia articles revision history within a day in a medium-scale
cluster, and supports flexible data structures for various kinds of semantic
web study.
