Bibliographic data
Existing databases or services providing substantial bibliographic data
The DBLP Computer Science Bibliography
The DBLP computer science bibliography contains the metadata of over 1.8 million publications, written by over 1 million authors in several thousands of journals or conference proceedings series.
Although DBLP started with a focus on database systems and logic programming (hence the acronym), it has grown to cover all disciplines of computer science.
Data
Resources list the full dump of the DBLP XML records (see http://dblp.uni-trier.de/xml/ - a simple DTD is available.
The paper "DBLP - Some Lessons Learned" documents technical details of this XML file. In the appendix "DBLP XML Requests" you may find the description of a primitive DBLP API.
Openness: OPEN
As of 2011-12-09 this data is open (relased under ODC-By). See the license information in the Readme.txt and the announce post: http://openbiblio.net/2011/12/09/dblp-releases-its-1-8-million-bibliographic-records-as-open-data/