Having the output of a console application in Visual Studio instead of the console

In the Tools -> Visual Studio Options Dialog -> Debugging -> Check the "Redirect All Output Window Text to the Immediate Window".

In the Visual Studio Options Dialog -> Debugging -> Check the "Redirect All Output Window Text to the Immediate Window". Then go to your project settings and change the type from "Console Application" to "Windows Application". At that point Visual Studio does not open up a console window anymore, and the output is redirected to the Output window in Visual Studio. However, you cannot do anything "creative", like requesting key or text input, or clearing the console - you'll get runtime exceptions.

Use System.Diagnostics.Trace

Depending on what listeners you attach, trace output can go to the debug window, the console, a file, database, or all at once. The possibilities are literally endless, as implementing your own TraceListener is extremely simple.