These are the latest softwares released by Adobe for Flash and Flex Developers. These three are for three related but different purposes. But one cant make out the differences by reading the above three Names. Flash Professional is the software one uses to create Flash animations.
Flash Catalyst is a tool to generate UI in mxml format to be used by the Flex application developer. Without Flash Catalyst, Application UI Designers would envision the application’s behaviour, color combination, and general look and feel and generate PNG/JPEG/PSD/AI and give it to developers along with printouts for the next state of user interactions. And then the develoeper’s code for it and end doing a stone age version of the fancy UI thought out by the designers. Flash Catalyst fills this gap. Designer’s Resources (images and PSD/AI files) can be imported into Flash Catalyst and one can create fully functional UI mockups. The only thing lacking would be the actual business logic. This can be saved and imported into Flash Builder for next level use by developers who will fill in the business logic.
Flash Builder is the name of the latest version of the Flex IDE developed by Adobe. The previous version was called Flex Builder, and this was built for the Flex 3 SDK. Flash Builder is targeted towards the latest version of Flex SDK version 4. With this one can build,debug and deploy Flex Applications.