ACPI administration advocacy advocacy advocacy opinion alsa amarok apache apple apt aptitude audio audo authentication automount avi awk bash BIOS boot business cache calendar calibre cdr cdrecord censorship commandline computerscience console convert cron cut database date debian degree design desktop development disk dpkg dvd economics education emacs email europe exim faad ffmpeg file files firefox firewall flash foss freedom ftp fun fuse git gnumeric graphics grep growisofs grub gtkpod hardware hardware html idiocy image imagemagick images installation ip iphone ipod iptables iso itunes ivman kde kernel keyboard knoppix lame laptop latex linux locale lockin longlines m4a microsoft mimetypes minitab mount mp3 mp4 mplayer multimedia music mysql network nfs nfs4 nmap openbox openoffice opinion opinion partition pdf perl php politics postgresql printing privacy programming rant remote rhythmbox rss rsync rxvt scp screengrab screenshot script scripting scsi security sed server shell siteadmin sitenews sitesoftware skype skype slackware sound sox spam spreadsheet ssh statistics subversion sudo svk swap t23 t43 terminal text thinkpad thunderbird time timezone ubuntu udev upgrade usb usbmount users uuid versioncontrol vfat video vnc windows wine wordpress wordprocessing X40 xwindows xwindows youtube
I recently wrote how difficult it was to read a fully marked up latex document. XML is, in my view, worse despite all the hype that it's human readable; mostly it's not.
Usually when you're writing something, you don't need a whole lot of markup, because the document's are not normally that complex. What's important is that whatever format you choose to finally display that document, works for that document. Lightweight markup is ideal for this end.
Another advantage of lightweight markup is that you don't need any bloated word processor or other complex programme; it can be edited in your favourite text editor.
There are plently of good lightweight markup languages that do the job and plenty of tools to convert them into formats for publication, such as Latex or HTML.
These are a few of the most popular. At the moment I'm using Textile, chiefly because it doesn't require long urls in the text, but allows them to be put at the bottom (or anywhere else) in the document.