Virtual reality (VR) is a technology that creates a simulated environment, typically experienced through a headset or other wearable device. VR is used in many applications, such as gaming, education, and training. Popular VR platforms include Oculus VR, HTC Vive, and PlayStation VR. See our products Test-driven development (TDD) is a software development approach where developers write automated tests before writing the code. TDD can help to improve code quality, reduce the number of bugs, and improve development efficiency. Popular TDD platforms include JUnit, NUnit, and PHPUnit.