I decided to have a look at Calibre, so I went to the related Wiki page (http://wiki.mobileread.com/wiki/Calibre
I found out that there is no direct link for the download of Calibre, or to the home page of Calibre.
There is only one link to the user manual and one to the Calibre sub-forum here at MobileRead.
I'd suggest adding at least a link to the home page, especially since I haven't found any link back to the home page from the user manual.
Heck, I can even try to do it myself, I just wanted to know if this had been a specific decision not to have those links up there or if this was just an oversight.