====== Ruby gems ======

As root:

<code>
cd src/rubygems-1.3.7
export RUBYOPT=""
ruby setup.rb
</code>

RUBYOPT is set in .bashrc to include ruby gems, but means that ruby will fail if it can't find a working gems install.

Gems commonly used:
  * mini_exiftool (which requires command-line tool [[http://www.sno.phy.queensu.ca/~phil/exiftool/install.html|exiftool]], source package Image-ExifTool-X.XX.tar.gz)
  * exifr (now rarely used in favour of mini_exiftool, which has read-write access)
  * fileutils

<code>
su  # gems can be installed for one user only but otherwise need to be run as administrator or root
gem update --system
gem install mini_exiftool
</code>

====== Qt4 ======

  * Qt4 (libraries and SDK, currently 400+MB): http://qt.nokia.com/downloads
  * qt4-qtruby: http://rubyforge.org/projects/korundum/

====== Qt Photo ======

  * exiftool
  * jhead
  * gems listed above