Hand-crafted lightweight Rest Client for testing APIs. Supports collections, environments, git collaboration and local storage.

Ranorex empowers software teams with comprehensive test automation tools that can handle even the most challenging user interfaces.

Built for developers and testers alike, SoapUI is the only open source tool that covers the entire testing spectrum (functional, security, load, mocking).

mabl is a low-code, intelligent test automation platform for Agile teams.

NUnit is a unit-testing framework for all .Net languages.

Burp or Burp Suite is a set of tools used for penetration testing of web applications. It is developed by a company named Portswigger who make freely available a Web Security Academy which has a range of lessons on penetration testing.