Correct way to reference software?
 

Hello,

For my PhD thesis I need to reference many software packages (eg afs, nfs, RedHat , Objectovity...etc). I am a physicist and so dont know the correct way to reference these - how would this be done in a computer science published paper? Perhaps the website address (eg redhat.com) or do papers get written about these kinds of software - if so which journals can I dig out the papers from?

Thanks,

Mark