http://securityintelligence.com/gartner-2014-magic-quadrant-siem-security/#.SzNnhshk
https://www.netiq.com/documentation/sentinel70/s701_user/data/bgrab5z.html
http://publib.boulder.ibm.com/tividd/td/tec/SC32-1234-00/en_US/HTML/ecodmst20.htm
http://complexevents.com/stanford/cep/
http://discovery.csc.ncsu.edu/software/correlator/
http://www.metaflows.com/wiki/Correlation_Engine_Rules
http://www.manageengine.com/products/netflow/asam-continuous-stream-mining-engine.html