browserling - Live interactive cross-browser testing from your browser.
Acunetix Vulnerability Scanner - Acunetix Vulnerability Scanner is a platform that offers a web vulnerability scanner and provides security testing to users for their web applications.
CrossBrowserTesting - Browser Testing made simple! Run automated, visual, and manual tests on 1500+ real browsers and mobile devices. Test more browsers, in less time.
Nessus - Nessus Professional is a security platform designed for businesses who want to protect the security of themselves, their clients, and their customers.
Sauce Labs - Test mobile or web apps instantly across 700+ browser/OS/device platform combinations - without infrastructure setup.
StackPath - Secure Content Delivery Network, DDoS, WAF Service