IBM QRadar is described as 'IBM® Security QRadar® SIEM consolidates log source event data from thousands of devices endpoints and applications distributed throughout a network' and is a Cloud Computing service in the business & commerce category. There are more than 10 alternatives to IBM QRadar, not only websites but also apps for a variety of platforms, including Linux, Windows, Self-Hosted solutions and Privilege Escalation Vulnerability Scan Tool. The best alternative is Qualys Cloud Platform. It's not free, so if you're looking for a free alternative, you could try Castle or Dynamite-NSM. Other great sites and apps similar to IBM QRadar are Ignyte Assurance Platform, Exabeam, Fortscale and Unified VRM by NopSec.
Qualys, Inc., is the most widely-deployed information security and compliance cloud solution in the world with over 7,700 customers including a majority of the Forbes Global 100 and a majority of the Fortune 100.