NUnit vs RSpec comparison of testing frameworks
What are the differences between NUnit and RSpec?

	NUnit https://nunit.org/	RSpec https://rspec.info
Programming language	.NET	Ruby
Category	Unit Testing	Unit Testing, Intergration Testing
General info	NUnit is an open-source unit testing framework for Microsoft .NET. NUnit was Initially ported from JUnit. Tests can be run from a console runner, within Visual Studio through a Test Adapter or through 3rd party runners. Tests can be run in parallel and has Strong support for data driven tests. Unit supports multiple platforms including .NET Core, Xamarin Mobile, Compact Framework and Silverlight.	Domain Specific Language (DSL) testing solution for Ruby code It focuses on empowering Test Driven Development (TDD). RSpec contains multiple smaller libraries, which may be independently used with other testing frameworks.
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	Yes Nunit is one of many programs in the xUnit family	Yes Yes, but it differs from more traiditional xUnit solutions. Its tests are written in a "Tests as Specification" manner. This means that the terminology used in RSpec is adjusted to a language more fitting for specification.
Client-side Allows testing code execution on the client, such as a web browser	Yes You can test front-end components with NUnit since it is a Unit testing framework the application is isolated into diverse modules which are tested independently	Yes RSpec is used to primarily test the behaviour of applications or individual components so it can test front-end behaviour as well - you can use capybara gem with RSpec for that.
Server-side Allows testing the bahovior of a server-side code	Yes You can test back-end components with NUnit, it is a Unit testing framework hence the application is isolated into diverse modules which are tested independently	Yes You can test server-side behaviour with Rspec
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes NUnit contains the fixture methods SetUp to initialize your test environment and TearDown method to destroy a test environment	Yes RSpec does contain fixture methods
Group fixtures Allows defining a fixed, specific states of data for a group of tests (group-fixtures). This ensures specific environment for a given group of tests.	Yes Group fixtures are available in NUnit	Yes Group fixture methods are supported
Generators Supports data generators for tests. Data generators generate input data for test. The test is then run for each input data produced in this way.	N/A	Yes RSpec contains generators for example intergration_'test_name' which will save a spec inside the spec/requests folder
Licence Licence type governing the use and redistribution of the software	MIT License	MIT License
Mocks Mocks are objects that simulate the behavior of real objects. Using mocks allows testing some part of the code in isolation (with other parts mocked when needed)	Yes You can create mock objects using the third party library moq	Yes Available through rspec-mocks gem.
Grouping Allows organizing tests in groups	Yes You can group tests into suites with NUnit	Yes Allows declaring example groups and contexts.
Other Other useful information about the testing framework