Washington and Lee University
"Information on terrorist events around the world since 1970... includes systematic data on international as well as domestic terrorist incidents that have occurred during this time period." From the National Consortium for the Study of Terrorism and Responses to Terror (START), supported by the U.S. Department of Homeland Security and the University of Maryland.
A "comprehensive, searchable and continuously updated database on all available information relating to terrorism, low intensity warfare and ethnic/communal/sectarian strife in South Asia." The site also includes the weekly South Asia Intelligence Review. Maintained by the Institute for Conflict Management (ICP).
Edward Mickolus' list of terrorists and related figures.
Searchable "compilation of speeches, interviews, statements, and publications of jihadist leaders, foot soldiers, and sympathizers. Nearly all content is in English translation..." (RAND Corporation)
The U.S. Counterterrorism Center (NCTC) provides a database of incidents dating from 1994.
Annual report to Congress on countries and groups. Formerly Patterns of Global Terrorism. (From the U.S. State Department).
This Jamestown Foundation site offers news, analysis, and several publcation series, including Terrorism Monitor.
Published in 2002, this encyclopedia contains over 300 signed entries on organizations, individuals, events, concepts, etc. You can view a list of entries here. (Sage).
A collection (2006) of about 200 documents, including "speeches, magazine and newspaper articles, memoirs, letters, interviews, novels, essays, and much more," on terrorism in the past three centuries. Each entry is accompanied by commentary of the document's context and significance. (Thomson Gale).
The ICT in Israel offers articles, reports, news, and other publications.