Abot
Fast and flexible C# framework for building customizable web crawlers
...It focuses on speed, flexibility, and extensibility while handling the complex low-level tasks involved in web crawling. It manages essential components such as multithreading, HTTP requests, scheduling, and link parsing so developers can focus on processing the collected data. Abot follows a modular architecture that allows developers to customize nearly every stage of the crawl process by implementing or replacing core interfaces. Abot exposes an event-driven model that enables applications to react to crawling events such as page completion or crawl restrictions. ...