Concordion vs Cucumber-JVM comparison of testing frameworks
What are the differences between Concordion and Cucumber-JVM?

	Concordion https://concordion.org/	Cucumber-JVM https://github.com/cucumber/cucumber-jvm
Programming language	Java	Java
Category		Acceptance Testing
General info	Concordion is a tool used to write and manage automated acceptance tests in Java based projects Concordion specifications are written in Markdown, HTML or Excel and then instrumented with special links, attributes or comments respectively. When the corresponding test fixture class is run, Concordion interprets the instrumentation to execute the test. Concordion lets you write them in normal language using paragraphs, tables and proper punctuation. This makes specification more natural to read and write, and helps everyone to understand and agree about what a feature is supposed to do.	Cucumber-JVM is a pure Java implementation of Cucumber The specifications are written in plain texts, which allows them to be easily understandable by all stakeholders.
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	No	No
Client-side Allows testing code execution on the client, such as a web browser	Yes You can specify tests for front-end components and functionality with concordion	Yes You can test the front-end part like the GUI using cucumber with serenity, they integrate well to test your front-end.
Server-side Allows testing the bahovior of a server-side code	Yes You can test server-side components and functionality with concordion.	Yes You can test back-end components such as API's using rest&soap clients, and databases
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes Concordion contains fixtures which correspond to a specific instrumentation within the code. That is when specifications are written they are instrumented with special links, attributes or comments which are then run with their corresponding fixtures	Yes Using the cucumber extension aruba you can create fixures in two steps: 1.Create a fixtures-directory; 2.Create fixture files in this directory
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 One can group fixtures in concordion	Yes You can group your fixtures inside your fixtures directories
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	N/A
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 By use of third party libraries like mockito	Yes By using all of RSpec’s supported mocking frameworks (RSpec, Mocha, RR, Flexmock)
Grouping Allows organizing tests in groups	Yes One can group tests into suites	Yes Cucumber allows the use of tag Cucumber feature files or individual tests to group tests. Then, you can pass a Cucumber tagged expression at test execution that specifies the tag (grouped) tests to run. https://www.toolsqa.com/cucumber/cucumber-tags/
Other Other useful information about the testing framework