What is Fluint 1.x?
Fluint (named dpUInt during its pre-release stage) was created by Digital Primates to push testing with Flex and ActionScript past basic unit testing and into the world of integration testing. It provides full support for unit testing in the tradition of FlexUnit, but goes further with richer asynchronous support and support for integration-level testing.
The maintainers of Fluint have pushed their best features into FlexUnit4, allowing for the widest support, development, and feedback. Additionally, compatibility is easier to maintain. In other words, if you are considering using fluint, just use FlexUnit4.