Fake is a web browser and automation tool for Mac OS X. The developer of the tool thinks that Fake could be considered as a mixture of Safari and Automator, and I happen to agree. The application allows you to configure, run, save and re-run actions that you normally do on the Web. The application can be highly customized to serve the purposes that you want it to serve.
As an example, on the developer's website, there is a screencast that shows how Fake can be used to automatically fill in HTML fields on a website. Whenever you register for an account somewhere, chances are that you are asked for your name, e-mail, etc. Well, by adding actions to a workflow, you can tell Fake what to do step by step. The way that is done in the example is as follows: an URL is opened, Fake is told what the fields ask and what information to return, and then, it is instructed to click on the "Finish" button. That is just an example of what Fake is useful for.
In short, this tool can be helpful and useful for people who constantly do the same thing over and over again on the web and maybe need to get that done automatically. If you simply want to fill HTML fields automatically on registration pages, Chrome can do that, and I am sure other apps can as well.