http://www.miller-group.net
Centre/SIS is a free student information system for public and non-public schools. Centre is a web-based, open source, student management product with features including student demographic info, scheduling, grade book, attendance, report cards etc.
http://www.focus-sis.org
Focus/SIS is an incredibly powerful tool for managing student data. The program includes gradebook, student records, attendence and is highly customizable.
http://richtech.ca/openadmin
Open Admin is a secure, web-based school administration program. It handles demographics, attendance, discipline records, report cards, grade books, online daybook plans, and special needs.
http://www.koha.org
Koha includes modules for circulation, cataloging, acquisitions, serials, reserves, patron management, branch relationships, and more.
http://openintel.os4ed.com
An open source data warehouse with custom report capabilities that is ideal for NCLB accountability.
http://www.schooltool.org
SchoolTool is a project to develop a common global school administration infrastructure that is freely available under an Open Source licence.