(Unit) Testing
Check
CppUnit
Jasmine
JUnit
Mocha
NUnit
PHPUnit
Spock Framework
TestNG
xUnit.net
Testing Libraries
AssertJ
Capybara
Code Contracts for .NET
Cofoja: Contracts for Java
Dumbster Email Testing
Fluent Assertions
HtmlUnit
junit-quickcheck
netDumbster
RestAssured
Timecop
WebDriver
WireMock
Mocking Frameworks
EasyMock
jMock
Fake Function Framework (fff)
Mockito
Moq
PowerMock
Behavior-driven Design, ATDD, Spec by Example
Concordion
Cucumber
FitNesse
RSpec
Specflow
Generative Testing
Model-based Testing
Combinatorial Testing
Advanced Combinatorial Testing System (ACTS)
ALLPAIRS Test Case Generation Tool
Provisioning and Containers
Chef
Docker
Jetty
Puppet
Spring Boot
Vagrant
Other
Checker Framework
Guava: Google Core Libraries for Java 1.6+
HSQLDB
Spec#
Sikuli