This is really big news for anyone working on open data as there are very few open data licenses available and none that provide for share-alike.
From the announce:
We are delighted to announce the release of v1.0 of the Open Database License (ODbL):
The Open Database License (ODbL) is an open license for data and databases which includes explicit attribution and share-alike requirements.
This license, the first of its kind, is a major step forward for open data. There are currently very few licenses available suited to data and databases and none which provide for share-alike (existing share-alike licenses such as the GPL, GFDL and CC By-SA are all unsuitable for data).
The development of the ODbL, has been a major effort extending over more than one and half years with an intensive consultation and review period for the last 6 months. We’d like to express our thanks to the communities and individuals who have contributed during this time.