This is a diagnostic feature that can be used to obtain more information about the workings of the NCrunch engine.
When loaded into the IDE, NCrunch creates a special-purpose output window for the dumping of trace information. For performance reasons, this output window normally is not used. Switching on the Log To Output Window configuration option will cause NCrunch to begin dumping trace information into the window where it can be inspected in order to troubleshoot problems.
The verbosity of the trace data output by NCrunch is controlled by the Logging Verbosity configuration setting.
Avoid enabling this setting unless there is something very specific you are looking for in the trace output. This setting will degrade responsiveness of the IDE while it is enabled, as data can only be logged to the output window using the foreground thread.
When searching for trace output that is specific to a task executed by NCrunch (for example, a particular build or test run), it is often easier to instead inspect the output of the task in the processing queue.
Note that the Logging Verbosity configuration setting defaults to Summary, which means that very little trace output will be shown unless this setting is changed.