racer

racer is A Rack-compliant ruby web server.

The following Rack app was used benchmark WEBrick, Unicorn, Thin and Racer:

run ->env { [200, { "Content-Type" => "text/html" }, ["hello world"]] }

Tests were carried out on a 64 bit Linux VM running on an Intel Core i7 980X.
ApacheBench was used to run the benchmarks with the following options:

ab -n 10000 -c <...> http://127.0.0.1:3000/

from https://github.com/charliesome/racer