* [Crawler v2.1.0](https://github.com/bda-research/node-crawler) – Node.js web crawler with Cheerio-based server-side DOM, configurable concurrency, rate limiting, retries, and prioritized request queue.

* [CrawlerDetect v1.2.15](https://github.com/loadkpi/crawler_detect) – Ruby gem for detecting bots, crawlers, and spiders based on user agent and HTTP headers.