Windmill vs Concordion comparison of testing frameworks
What are the differences between Windmill and Concordion?

Windmill

https://pypi.org/project/windmill/

Concordion

https://concordion.org/
Programming language

Python

Java

Category

UI Testing

General info

Windmill is an Open Source Web UI testing framework for Python

Windmill is an Open Source AJAX Web UI testing framework that implements in-browser recording and playback, cross browser testing and test integration

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.
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

Its main function is testing of front-end components and functionality

Yes

You can specify tests for front-end components and functionality with concordion
Server-side
Allows testing the bahovior of a server-side code

No

Yes

You can test server-side components and functionality with concordion.
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

N/A

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
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.

N/A

Yes

One can group fixtures in concordion
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.

Yes

By using third party libraries

N/A

Licence
Licence type governing the use and redistribution of the software

Apache License 2.0

Apache License 2.0

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)

N/A

Yes

By use of third party libraries like mockito
Grouping
Allows organizing tests in groups

N/A

Yes

One can group tests into suites
Other
Other useful information about the testing framework