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.

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

Swagger UI allows anyone — be it your development team or your end consumers — to visualize and interact with the API’s resources without having any of the implementation logic in place

Streamline your API testing, integration testing and test data management.

Unifying API testing, API Performance testing, API Mocks and UI testing.

Voiden is a developer-first API client with local storage, Git-integrated, all based on markdown + offline support.