1. Key difference 1: Use case and purpose: Mock/it is a library used for mocking HTTP requests in unit tests, while Refit is a library used for creating REST API clients. Mock/it is primarily used to simulate HTTP responses for testing purposes, allowing developers to isolate and test specific parts of their code that interact with HTTP resources. On the other hand, Refit is used to generate type-safe HTTP clients based on interfaces, making it easier to consume REST APIs in a strongly-typed manner.

2. Key difference 2: Integration with testing frameworks: Mock/it is designed specifically for integration with popular testing frameworks like JUnit, Mockito, and PowerMock. It provides annotations and utilities that allow developers to easily mock HTTP requests and responses within their unit tests. Refit, on the other hand, is a standalone library that focuses on simplifying the creation of REST API clients, without any specific ties to testing frameworks.

3. Key difference 3: Workflow and usage: Mock/it is typically used in scenarios where developers need to mock HTTP requests and responses to test their code's behavior when interacting with external services. It allows developers to define custom mock responses and behavior, making it easier to test different edge cases. Refit, on the other hand, is used to generate HTTP clients based on interfaces, simplifying the consumption of REST APIs by automatically handling serialization, deserialization, and network communication.

4. Key difference 4: Dependency management: Mock/it is often used as an additional library within a project, requiring developers to explicitly add it as a dependency and configure their testing framework to integrate with it. Refit, on the other hand, is commonly used as a standalone library that can be easily added to a project through package managers like NuGet or through manual installation.

5. Key difference 5: Development community and support: Both Mock/it and Refit have active development communities and are well-maintained. However, Refit has gained popularity due to its ease of use and integration with popular frameworks like Xamarin and .NET. It has extensive documentation, community support, and regular updates, making it a preferred choice for developers looking to build REST API clients.

6. Key difference 6: Performance and overhead: Mock/it is primarily used for testing purposes, and its main focus is on providing an easy way to mock HTTP requests and responses during unit tests. It may introduce some overhead and complexity due to the configuration required for mocking. Refit, on the other hand, is optimized for creating efficient and performant REST API clients. It generates code that minimizes overhead and provides optimized handling of HTTP requests and responses.

In Summary, Mock/it is a library for mocking HTTP requests in unit tests, while Refit is a library for creating REST API clients. Mock/it is focused on testing and integration with testing frameworks, while Refit simplifies the creation of type-safe HTTP clients based on interfaces.