The Twilio API Explorer is a new tool designed to simplify the process of building telephony applications by providing an easy-to-use interface for making requests to Twilio's REST API, exploring responses, and copying code snippets. The API Explorer now allows developers to access a wider range of REST API requests through the browser, including operations not previously available from the web portal. This enhancement aims to make it easier for developers to integrate Twilio into their applications, with support for generating snippets in curl and Ruby helper library, and plans for future language support.