ComponentPen is a Blazor component that emulates CodePen's functionality within a Blazor application. It allows users to input HTML, CSS, and JavaScript code, dynamically render the output, and interact with saved components. This tool offers an interface for writing and previewing Blazor components on the fly by leveraging advanced features such as dynamic component rendering, reflection, JavaScript interop, and state management using browser storage. The component comprises a user interface built with Radzen Blazor components and a code-behind that handles dynamic rendering and state persistence.