Queue module don't exist on drupal 5/6

Hi there!

I don't know if it's a bug or a documentation question.

I'm testing the module and realized that one of the functionalities - "queue" - exists on the drupal API at drupal 4.7; on 5.x and 6.x it has been taken out of core.

What's the module that we should use? Because now, one must use an external module if want to use 'queues' (like me).