Running with no muffler

Is this safe for the engine? I have heard things about not enough backpressure and things about horsepower gains and losses. I have heard that the less resistance on the exhaust gas the better. And I assume it very much depends on where you actually remove the pipe(at the headers, or run a pipe with no cat and/or muffler.

The lower the restriction is the better it is.

So I can take my muffler off?

In general, yes. There might be some problems with engine management, but that you will notice.