Which tool is needed for developing an ActiveGate Extension?

To develop an ActiveGate Extension, the pluginSDK is necessary because it provides the essential tools and libraries specifically designed for creating extensions that enhance Dynatrace ActiveGate functionality. The pluginSDK includes boilerplate code, sample extensions, and APIs that streamline the development process, ensuring compatibility with the Dynatrace ecosystem.

The other options, while useful in various development contexts, do not directly support the creation of ActiveGate Extensions. The Java Development Kit, for instance, is typically used for Java application development but does not cater specifically to the requirements of Dynatrace extensions. Similarly, the Node.js framework and PHP environment are relevant for web application development but are not tailored for the specific needs and functionalities that the pluginSDK offers for ActiveGate development.