Procedures are the real weapons that make a hacker go. They are very
specialized, yet also very adaptive code fragments. Ready to exploit certain
well known (or in most cases not so well know) bugs of a system. They are by
far not as versatile as a library, but at least as useful.
There is a huge number of procedures around, countless almost. It is even
possible to create ones own procedures. However that task is expensive and
tiresome. So it is strongly suggested to obtain already pre-made stuff.
Exclusive stuff is often a kind of status symbol and trademark of the best, but it can never fully replace the versatility that is also needed.
To clear up the confusion, a bit about all the different types of procedures - a
rough classification - has been established. It covers most of the well-known
stuff. But of course there might be quite some more effects out there. There are even procedures that cause more then one effect.
Also for most procedures there are various methods of delivery.
Some procedures only attack one target; some two, three or even up to four.
Other procedures are not that aimed and attack everyone in the system. More
sophisticated stuff might even attack everybody but you. Very useful indeed, but also usually too expensive.
Also one should note that unlike libraries most procedures can be copied easily, thus making them a second 'currency' besides cash. Some procedures
might even have a higher value then a small house for those who know about