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

An open source JS tool for image analysis and comparison. A successor of PhantomCSS.

Automation Test Reporting. OSS, Language & Framework agnostic

Best "simple" screen capturing app (Mac and Windows) because it creates animated gifs that attach to bugs easily. Simple because it works a lot like snippy to capture screen areas

Checks web UI for browser compatibility (Compliance with Can I Use?)

A screenshot/screenvideo tool! Also allows you to do basic alterations to the screenshots (arrows, blur, ...)