wrk is described as 'modern HTTP benchmarking tool capable of generating significant load when run on a single multi-core CPU. It combines a multithreaded design with scalable event notification systems such as epoll and kqueue'. There are more than 10 alternatives to wrk for a variety of platforms, including Linux, Windows, Mac, Online / Web-based and Self-Hosted solutions. The best alternative is Apache JMeter, which is both free and Open Source. Other great apps like wrk are Tsung (Free, Open Source), Gatling (Free, Open Source), Apache Benchmark (Free, Open Source) and Storm.dev (Freemium).
Apache JMeter is an open source Java application, designed to load test functional behavior and measure performance. Originally designed for testing Web Applications, it has since expanded to other test functions as well.
Tsung (formerly IDX-Tsunami) is a distributed load testing tool. It is protocol-independent and can currently be used to stress HTTP, WebDAV, SOAP, PostgreSQL, MySQL, LDAP and Jabber/XMPP servers. It is distributed under the GNU General Public License version 2.
ab is a tool for benchmarking your web server. It is designed to give you an impression of how your current web server installation performs. This especially shows you how many requests per second your web server installation is capable of serving.
A collaborative network of nodes. Storm is the way to improve the management of your web application. Manage, monitor and stress test your web resources. Automation server, workflow, continuous integration, automatic development.
AppPerfect Load Test is a fully automated load test, stress test and performance test solution that helps you design and simulate thousands of users in a realistic manner which can be used to load test your application infrastructure for performance, reliability and scalability.