Open Source and freeware/donationware/shareware/ resources for K12

Open Source Educational Resources (OER) Commons

K12 Linux Project

Open Source Content Management System with no PHP required
Moodle is a free course management system (CMS)

UBUNTU - Complete (and bootable) system and applications, now with a specific builds, with one for K-12 education.

GIMP is a painting program (pixel level editor), often packaged in builds like UBUNTU

FreeMind mind mapping tool

Audacity - audio recording, mixing and export features

SiteSucker does just what you thought. Be aware that FireFox has some of these
same features ( and oh, so much more!) available with add-ons.

OpenOffice is a productivity package for Linux, Apple, and Windows
NeoOffice is a productivity package for Apple

Creative Commons- Share, reuse, and remix — legally.

Free University

MIT is committed to advancing education and discovery through knowledge open to everyone.
MIT OCW shares free lecture notes, exams, and other resources from more than 1800 courses spanning MIT's entire curriculum
MIT Open-courseware

ImageJ is an image processing and analysis toolset

Viz Tools organized at Google

Attribution ShareAlike copyright V3.0 (unported)

Scott Coletti