Thor is WebSocket benchmarking/load generator. There are a lot of benchmarking tools for HTTP servers. You've got ab, siege, wrk and more. But all these tools only work with plain ol HTTP and have no support for WebSockets - even if they did they wouldn't be suitable, as they would be testing short running HTTP requests instead of long running HTTP requests with a lot of messaging traffic. Thor fixes all of this. Thor requires Node.js to be installed on your system. If you don't have Node.js installed you can download it from http://nodejs.org or build it from the github source repository: http://github.com/joyent/node.