Audio in Linux

This is probably a stupid question, but how can I get the audio output in Linux?  Reading from /dev/dsp only gives me input from the microphone.

On Linux there are in general two different sound systems that provide drivers to your sound device, OSS and the more recent ALSA. Additionally, advanced sound servers such as PulseAudio and JACK can use ALSA to provide professional audio features such as routing of inputs and outputs, high quality mixing and resampling, aggregation of devices or sound cards and (in the case of JACK) very low latencies.