Ravan is a JavaScript based Distributed Computing system that can perform brute force attacks on salted hashes by distributing the task across several browsers. Ravan uses HTML5 WebWorkers to start background JavaScript threads in the browsers of the workers, each worker computes a part of the hash cracking activity. The main page would constantly monitor the progress of the cracking process and manage it across all the workers. You would be able to see the stats throughout the process, once the hash is cracked the clear-text value is displayed.
Source: https://thehackernews.com/2010/12/ravan-distributed-hash-brute-forcer.html