JUnit vs Fluent Assertions: What are the differences?

JUnit: A programmer-oriented testing framework for Java. JUnit is a simple framework to write repeatable tests. It is an instance of the xUnit architecture for unit testing frameworks; Fluent Assertions: Library to build fluent assertions for unity testing. A very extensive set of extension methods that allow you to more naturally specify the expected outcome of a TDD or BDD-style unit tests. Targets .NET Framework 4.5 and 4.7, as well as .NET Core 2.0, .NET Core 3.0, .NET Standard 1.3, 1.6 and 2.0.

JUnit and Fluent Assertions belong to "Testing Frameworks" category of the tech stack.

JUnit is an open source tool with 7.7K GitHub stars and 2.92K GitHub forks. Here's a link to JUnit's open source repository on GitHub.