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

Windmill

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

SimpleTest

https://github.com/simpletest/simpletest
Programming language

Python

PHP

Category

UI Testing

Unit Testing, Web 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

SimpleTest is a unit test and web test framework for PHP

It has JWebUnit style functionality and support for SSL, forms, frames, proxies and basic authentication
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

With SimpleTest common but fiddly PHP tasks, such as logging into a site, can be tested easily
Server-side
Allows testing the bahovior of a server-side code

No

Yes

Server-side behaviour can be tested by writing simple unit tests to test functionality and behaviour of single components.
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

It can import fixtures using a mixin like 'given()' method
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

It allows grouping of fixtures
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

Yes

Simpletest has support for generators
Licence
Licence type governing the use and redistribution of the software

Apache License 2.0

GNU Lesser General Public License v2.1

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

It allows for one to build Mock objects.To create a mock version of a class we need to include the mock object library and run the generator. This will create a clone class which we use to create new instances(objects) in our test cases.
Grouping
Allows organizing tests in groups

N/A

Yes

There are several ways of grouping tests; one is to simply place multiple test cases into a single file, another is to mark any base test cases that should not be run as abstract, Simpletest gives you a couple of options
Other
Other useful information about the testing framework