Thank you guys for your help.
Mythtv is a very heavy program (a media center); I dont really want something like that on my old computer. Democracy (I already know it) is good but slow. Penguintv is a light alternative but is empty and I dont really know how to add video feeds there; so I finally kept Democracy (73 MB with its depedencies !).
I know gtk-gnutella. I also found apollo and mldonkey that have access to many networks. Apollo (based on gift) caused me problems. It copied all my /home/user in its shared folder. I saw this as a risk and I uninstalled it. Does anyone have a similar experience?
Mldonkey looks cool. I am trying to find the right ports now....
For web creation I was thinking of Nvu as well; I read somewhere that it supports templates. This is pretty helpful and if I could find templates on the web it would be even prettier...
Now, another question: if anybody knows Reconstructor, what's your opinion about it? Did it work well for you? For me it gave no result...

Maybe because I put a lot of apps to install and to remove...