VMware
Nessus offers Free Trial, but Nucleus does not.
Nucleus is designed for Large Enterprises and Medium Business.
Nessus is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Nucleus Starts at $11/Year whereas for Nessus Starts at $2,790/Year.
Some top alternatives to Nucleus includes InsightVM, BeyondTrust Vulnerability Management, Qualys VM, Nessus, Microsoft Threat Vulnerability Management, Flexera Software Vulnerability Management, ManageEngine Vulnerability Manager Plus, Kenna Security, Unified VRM and Snyk.
Some top alternatives to Nessus includes Tenable.io, BeyondTrust Vulnerability Management, Qualys VM, Microsoft Threat Vulnerability Management, Flexera Software Vulnerability Management, ManageEngine Vulnerability Manager Plus, Unified VRM, Acunetix, Qualys Patch Management and Qualys Cloud Platform.