Siege is load testing tool and its a open source tool, learning is very simple, it support multiple platform and its latest version 4.0.2 and if you are using linux os only need this command to install
brew install siege
Currently I'm working in siege tool. I am checking the load of my server using siege tool and monitoring linux top command. First i run the load test with a relatively small number of concurrent users. then i check the siege output . In the outptut i can see that transcation, no .of hits in the server, elapsed time duration of entire test, data transfered, it is the sum of data transfered to every siege simulated user, response time, concurrency, no. of succesful transaation, failed transaction.
I'm saying that Siege (like any other tool) can only simulate some limited number of users.
Siege is very easy to learn only go through the siege documentation.
siege does not have enough features compare with other other tool, but easy to learn