Ruby In Steel Developer includes the integrated 'Cylon' debugger. This provides a fast debugging solution for Ruby and Rails applications. It allows you to set breakpoints, navigate the call stack, monitor watch variables and drill down into variables to view the inner details in the form of an expandable outline. As an alternative, you may select to debug using a slower Ruby debugger. Neither of these debuggers is currently multithreaded. When debugging Rails applications, we recommend using the LightTPD server see: Debugging Rails With Cylon).