These data sets either employ Correlates of War country codes, derive from, or build upon, core COW datasets (e.g. alliance, militarized dispute, war, state membership data) and are largely compatible with COW coding rules and other COW data sets.
CShapes: (historical maps of state/capital boundaries)
The Computational Event Data System (follow-on to the KEDS System)
Peace and Rivalry data from Goertz, Diehl, and Balas. These data are described in Goertz, G., Diehl, P. and Balas, A. 2016. The Puzzle of Peace: Explaining the Rise of Peace in the International System. Oxford University Press.
Other Major Data Projects
These represent a selection of the major resources and data sets frequently used by scholars in quantitative international relations. These links represent not simply replication data sets, but time-series-cross-sectional datasets on core variables.
Correlates of War Book Series from CQ Press
This book series is a result of a collaboration between the COW Project and CQ Press.
International Military Alliances: 1648-2008. (2008). Douglas M. Gibler.
Resort to War: 1816-2007. (2010). Meredith Reid Sarkees and Frank Whelon Wayman.
Handbook of International Rivalries. (2011). William R. Thompson and David Dreyer.
A Guide to Intra-state Wars: An Examination of Civil, Regional, and Intercommunal Wars, 1816-2014. (2016). Jeffrey S. Dixon and Meredith Reid Sarkees.
These documents contain particularly helpful discussions or information about data sets in international relations.