OFSET is the Organisation for Free Software in Education and Training. We maintain some packages, which are necessary for the distribution of Education free software we make, Freeduc-CD. These efforts are being merged into Debian. However, you may find here some packages with newer versions.
To get OFSET's Debian packages, add the following lines in your file sources.list:
# ofset's packages
deb http://debian.ofset.org etch main
deb-src http://debian.ofset.org etch main