GitHub project

Citrus is a test framework written in Java that enables automated integration testing of message-based EAI applications. The tool can easily simulate surrounding systems across various transports and protocols (e.g. JMS, SOAP WebServices, Http, TCP/IP, ...) in order to perform end-to-end use case testing.
Citrus provides strong validation mechanisms for XML message contents and allows to build complex testing logic. Citrus supports you with features such as:  Sending and receiving messages, Database validation, Automatic retries, Variable definitions, Message timeout simulation, Dynamic message contents, Error simulation, Iterations and many more

Advantages:

Cerberus is a web-application, open source, test repository, user-friendly, can interface with a robot in multiple technologies.

Firing Range is a test bed for web application security scanners, providing synthetic, wide coverage for an array of vulnerabilities. Firing Range was developed by Google in the hopes of building a test ground for automated scanners. Firing Range doesn't focus on creating realistic-looking testbeds for human testers. Instead, the tool uses automation to exhaustively enumerate the contexts and the attack vectors that an application might exhibit. It is built entirely on Google technologies like Chrome and Google Cloud Platform, with support for the latest HTML5 features, a low false positive rate, and ease of use in mind.

A Ruby gem for writing powerful tests in Rails apps with very little code. Shoulda-matchers provides Test::Unit- and RSpec-compatible one-liners that test common Rails functionality. These tests would otherwise be much longer, more complex, and error-prone.If you're not testing a Rails project or don't want to use the matchers, you can use shoulda-context independently to write tests

Karma is a test runner for JavaScript that runs on Node.js. It is very well suited to testingAngularJS or any other JavaScript projects. Using Karma to run tests using one of many popular JavaScript testing suites (Jasmine, Mocha, QUnit, etc.) and have those tests executed not only in the browsers of your choice, but also on the platform of your choice (desktop, phone, tablet.) Karma is highly configurable, integrates with popular continuous integration packages (Jenkins, Travis, and Semaphore) and has excellent plugin support.

Chakram is an API testing framework designed to perform end to end tests on JSON REST endpoints.

The library offers a BDD testing style and fully exploits javascript promises - the resulting tests are simple, clear and expressive. Chakram is built on node.js, mocha and chai.

This readme offers an introduction to the library. For more information, visit Chakram's documentation and tests which demonstrate all of Chakram's capabilities. In addition, example tests of publicly accessible APIs are available in the examples directory. If required, assistance can be found in the project's gitter chat room.

Galen is a test framework originally designed for testing layout of web applications but is also a great tool for functional testing. When it comes to testing a responsive layout it works in the following way:

• Open a page in browser
• Resize it to specified size
• Test the layout according to user-defined specs

It uses Selenium for interacting with elements on the page and getting their locations and dimensions. 
Once it sees that something is wrong - Galen reports the error, makes a screenshot and highlights the misbehaving element on it.

Tsung is a distributed load testing tool and an open source tool written in Erlang. It is protocol-independent and can currently be used to stress Jabber/XMPP, HTTP, SOAP, LDAP and PostgreSQL servers (SSL is supported). It simulates complex user's behaviour using an XML description file, reports many measurements in real time (including response times, CPU and memory usage from servers, customized transactions, etc.). HTML reports (with graphics) can be generated during the load. For HTTP, it supports 1.0 and 1.1, has a proxy mode to record sessions, supports GET and POST methods, Cookies, and Basic WWW-authentication. It has already been used to simulate thousands of virtual users.

Karate enables you to script a sequence of calls to any kind of web-service and assert that the responses are as expected. It makes it really easy to build complex request payloads, traverse data within the responses, and chain data from responses into the next request. Karate's payload validation engine can perform a 'smart compare' of two JSON or XML documents without being affected by white-space or the order in which data-elements actually appear, and you can opt to ignore fields that you choose.

Since Karate is built on top of Cucumber-JVM, you can run tests and generate reports like any standard Java project. But instead of Java - you write tests in a language designed to make dealing with HTTP, JSON or XML - simple.

Protractor is an end-to-end test framework for AngularJS applications.
Protractor runs tests against your application running in a real browser, interacting with it as a user would. Protractor is built on top of WebDriverJS, which uses native events and browser-specific drivers to interact with your application as a user would.
Protractor is intended for end to end or integration testing. Big tests in which you have a running instance of your entire application should be run using Protractor.
Protractor is intended to run tests from a user's point of view - if your test could be written down as instructions for a human interacting with your application, it should be an end to end test written with Protractor.

Test-driven database development. Write readable, easy-to-maintain unit and integration tests for your database code. DBFit is a part of FitNesse, itself an implementation of the FIT acceptance testing framework. DBFit is directly targeted at database testing. Tests are written as wiki tables with a query or procedure execute followed by a listing of the expected results.  It can handle direct SQL, stored procedures, or, with a bit of simple customization, custom procedures. 

Windmill is no longer actively maintained but still available for download from GitHub, see link inside

XMLUnit is an open source project licensed under the BSD license. It provides a small library of interrelated classes that simplify each of the different ways to test XML pieces that have been outlined in the previous section. Special APIs are provided to simplify writing unit tests with J/NUnit, but the library itself is fully usable without any testing framework at all. There is a Java and a .NET version of XMLUnit. XMLUnit’s APIs will accept “pieces of XML” as input using several different forms. In most cases they can be provided as InputStreams, Readers, Strings, InputSources or readily parsed DOM Document instances. XMLUnit also provides a Transform class that can be used to apply an XSLT transformation to an existing input.

Robolectric is designed to allow you to test Android applications on the JVM based on the JUnit 4 framework. Robolectric is a framework that allows you to write unit tests and run them on a desktop JVM while still using Android API. Robolectric mocks part of the Android framework contained in the android.jar file. Robolectric provides also implementations for the methods while the standard Android unit testing support throws exceptions for all Android methods.

This enables you to run your Android tests in your continuous integration environment without any additional setup.Robolectric supports resource handling, e.g., inflation of views. You can also use the findViewById() to search in a view.

MiniTest, as the name suggests, is a small and fast unit testing framework. Shipped with Ruby 1.9, MiniTest supports a complete suite of testing capabilities such as TDD, BDD, mocking, and benchmarking. Since ruby 1.9 the ruby standard library has included a testing framework called MiniTest, it is a modern and lightweight replacement for ruby 1.8's Test::Unit framework. MiniTest provides:

•     Unit tests with MiniTest::Unit
•     Specs with MiniTest::Spec
•     mock objects with MiniTest::Mock
•     algorithm performance tests

AutoHotkey (AHK) is a free, open-source macro-creation and automation software for Windows that allows users to automate repetitive tasks. It is driven by a scripting language that was initially aimed at providing keyboard shortcuts, otherwise known as hotkeys, that over time evolved into a full-fledged scripting language. And if you're really interested, here's a great video about it 

TestCafe is a pure node.js end-to-end solution for testing web apps. It takes care of all the stages: starting browsers, running tests, gathering test results and generating reports. TestCafe doesn’t need browser plugins - it works in all popular modern browsers out-of-the-box.

Freshen is an acceptance testing framework for Python . uses the (mostly) same syntax as Cucumber. Why copy Cucumber? - Because it works and lots of people use it. Why use Nose? - Because it works and lots of people use it and it already does many useful things. No need to spend time in re-implementing coverage, profiling, test discovery, and command like processing again. Freshen supports 30 languages, exactly the same as cucumber, since the "language" file was borrowed from the cucumber project. As long as your .feature files respect the syntax, the person in charge of writing the acceptance tests may write it down.

PhantomJS is a scripted, headless browser used for automating web page interaction.
PhantomJS provides a JavaScript API enabling automated navigation, screenshots, user behavior and assertions making it a common tool used to run browser-based unit tests in a headless system like a continuous integration environment.
PhantomJS is based on WebKit making it a similar browsing environment to Safari and Google Chrome(before Chrome's fork of WebKit evolved into Blink). It is open-source software released under the BSD License.

RedwoodHQ is a free Open Source test automation framework that allows multiple users to develop automation code, create readable action/keyword driven test cases and execute them all under a single Web interface.
RedwoodHQ supports any Java/Groovy code or test tools like Selenium, Appium, etc., can be used for back-end as well as front-end automation.

Robotium is a test framework created to make it easy to write powerful and robust automatic black-box test cases for Android applications. With the support of Robotium, test case developers can write function, system and acceptance test scenarios, spanning multiple Android activities. 
Robotium has full support for Activities, Dialogs, Toasts, Menus and Context Menus.       

PHPUnit is a unit testing software framework for the programming language PHP. Created by Sebastian Bergmann, PHPUnit is one of the xUnit family of frameworks that originated with SUnit. It uses assertions to verify that behavior of the unit of code under test behaves as expected. PHPUnit is the de-facto standard for unit testing in PHP projects. It provides both a framework to write the tests as well as the functionality to run the tests and analyze their results. It supports the development of object-oriented PHP applications using the concepts and methods of Agile Programming, Extreme Programming, Test-Driven Development, and Design-by-Contract Development.

Celerity is a JRuby library for easy and fast functional test automation for web applications. Celerity is a JRuby wrapper around HtmlUnit – a headless Java browser with JavaScript support. It provides a simple API for programmatic navigation through web applications.Celerity provides a superset of Watir's API.

Visual Assert is a Visual Studio® AddIn that allows you to easily write, manage, run, and debug your C/C++ unit tests – without ever leaving the Visual Studio® IDE. No fiddling with command line tools, no complex configuration, and no boilerplate code required. Visual Assert (formerly code-named cfix studio) is based on, and fully compatible to the open source unit testing framework cfix.