What two rival development environments are used to provide interactive web applications and video content?

Flash and Silverlight are both technologies that were designed to enable rich multimedia content and interactive applications on the web. Flash, originally developed by Macromedia and later acquired by Adobe, was widely used for animations and video playback, allowing for the development of interactive web applications. It utilized ActionScript for scripting interactivity.

Silverlight, developed by Microsoft, served a similar purpose, offering tools to create rich media applications and to display video content alongside interactivity within a web browser. Each of these environments provided capabilities for developers to create immersive experiences that went beyond standard HTML, allowing for animations, vector graphics, and video playback integrated directly into web pages.

While other options may provide functionality related to web development or programming, they do not specifically match the description provided in the question regarding rival interactive capabilities primarily focused on multimedia web applications. For instance, HTML and CSS are foundational technologies for web design, Java and Python are general-purpose programming languages used for a variety of applications, and PHP and ASP.NET are server-side scripting languages designed for server operations, rather than direct interactive content on the client side.