Recently, I've stumbled upon an interesting question about the difference between Linux and FreeBSD ([Why would someone choose FreeBSD over Linux?](https://unix.stackexchange.com/questions/14489/why-would-someone-choose-freebsd-over-linux)) and found there a link to this [site](http://www.over-yonder.net/~fullermd/rants/bsd4linux/01). I've read that the main difference is that Linux is just a kernel and FreeBSD is a complete OS with many integrated packages in it, that work seamlessly.  

So my question is:

Where can I read about those packages, I mean is there some page which lists all packages built into the system?