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

Windmill

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

Fuchu

https://github.com/mausch/Fuchu
Programming language

Python

.NET

Category

UI Testing

Unit 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

Fuchu is functional test library for F# / C# / VB.NET

Fuchu is a test library for .NET, that supports C# and VB.NET but with a special focus on F#. It draws heavily from Haskell's test-framework and HUnit.
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 test front-end components by testing individual front-end classes and modules
Server-side
Allows testing the bahovior of a server-side code

No

Yes

You can test back-end components by testing individual back-end classes and modules
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 do TestFixtureSetups (SetUp/TearDown), but not TestFixtureTearDowns (not unless you treat that test suite separately)
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

Group fixtures are available in Fuchu
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

You can create mock objects using the third party library moq
Grouping
Allows organizing tests in groups

N/A

Yes

You can organize tests in suites and give them names
Other
Other useful information about the testing framework