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

Quick

https://github.com/quick/quick

RSpec

https://rspec.info
Programming language

Swift

Ruby

Category

Acceptance Testing, Unit Testing

Unit Testing, Intergration Testing

General info

Quick is a Swift (and Objective-C) testing framework.

Quick is a behavior-driven development framework for Swift and Objective-C that is inspired by RSpec, Specta, and Ginkgo. Quick comes bundled with Nimble a matcher framework for your tests.

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

Yes, it is an xUnit style test framework

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

Developers can test front-end behaviour and components by defining front-end feature specifications

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

Developers can test back-end behaviour and components by defining back-end feature specifications

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

Quick contains fixture methods setup() and teardown() for setting up and destroying test environments

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

Yes, example groups (logical groupings of examples/tests) can share setup and teardown code

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

Apache License 2.0

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

Yes, developers can create mock objects with Quick using the Cuckoo library

Yes

Available through rspec-mocks gem.
Grouping
Allows organizing tests in groups

Yes

In Quick test suites are named Specs, and every test suite you create starts off with a class inheriting from QuickSpec includes a main method, spec() which contains all the test cases.

Yes

Allows declaring example groups and contexts.
Other
Other useful information about the testing framework