What's the best free audio track INFO editor?

[Curt]

Some friends of mine have recorded and published a music CD. When I tried to transfer it to my PC the first problem was that RealPlayer 11+ didn't fully recognize the files as being audio format at all, so I had to use Nero. However, this is not important right now. But the second problem was that there were no informations at all to see. No track name, other than Track1, etcetera, and no info on the artists, no nothing. And in my little head this is now an important problem.

So I wanted to edit these infos myself, but realized that I have no editor to do so. Of course any of my Windows Media Player 11, RealPlayer 11, WinAmp 5.5 Pro, can do so, but the informations these apps can edit are too 'poor', if you know what I mean. I want to give it all the infos that normally are required on a music CD: Who wrote the text, who did the music, and when, and where, and so on - all it can have!

So I came here to ask you guys:
What is The Best gratis audio track INFO EDITOR, please??

[Lashiec]

Pick your poison, but it looks there's a clear winner.

[Curt]

I never took any interest in tagging, and now I realize I had no clue what it meant - I guess I thought it was all about genre. Is this really all media info is about: tagging? Hmm... well, I am glad to hear it is that simple - now I have the final reason to use (and learn to use) my MP3tag... right now its' first greating said "this version was released quite some time ago, do you want to update?"   

Thanks for enlightening me!

Edit:PS!
I would say MP3-Info also sounds interesting (though it too "was relased quite some time ago"). Edit2: There really are a lot of interesting apps mentioned!