![[Home]](../images/gif/logo.gif "Home"){kind=logo}
![[background]](../images/gif/nav.bg.gif "background"){kind=small}
![[pros and cons]](../images/gif/nav.pros.gif "pros and cons"){kind=small}
![[k12 examples]](../images/gif/nav.examplesx.gif "k12 examples"){kind=small}
![[decisions]](../images/gif/nav.decisions.gif "decisions"){kind=small}
![[appendices]](../images/gif/nav.appendices.gif "appendices"){kind=small}
Most of the programs described here are available through the freshmeat network. Open source can be used for:
Backend solutions typically involve many servers, routers, cable, and other intimidating hardware. These solutions are the critical heart of a network. The backend must be reliable and secure, or users and their computers are isolated from each other or jeopardized. Over the past decade, schools have become more dependent on the backend. Resources like email and the World Wide Web are becoming essential to effective instruction and administration. The staff assigned to the backend typically have the freedom to design and deploy any solution, proprietary or open source. They are apparently most influenced by reliability. While it's irritating to restart a desktop computer, an unreliable network server can affect everyone. Security is also a major concern.
A server needs an operating system. There are two major open source operating systems, Linux and BSD. Current users apparently prefer Linux, especially Red Hat, Mandrake, SuSE, Fedora, and Linspire. Most of the following solutions run on Linux.
File servers
Linux was designed for networking. Linux excels as a server operating system by maximizing speed and reliability, scaled up to virtually any number of nodes and users. Most of the following solutions are (in essence) special file servers. For essential network architecture, open source solutions include Netatalk (for Apple clients) and Samba (for Windows clients). Such solutions offer a low threshold for experimentation and incremental migration without affecting most users, since changing the server software doesn't visibly affect their desktop/windows interfaces.
Web hosting
Current users prefer Apache for Web hosting. Apache represents the most mainstream example of open source: more than 72% of the Web runs on this open source program. (Serverwatch, 2004) The popular LAMP solution uses Linux, Apache, MySQL, and PHP/Perl to offer dynamic Web content using scripts, applets, and relational databases. (You can identify some LAMP Web sites by looking for ".php" in the address.) Python is also a popular open source tool for Web hosting.
Regardless of whether the client is proprietary or open source, almost all email solutions include some open source software. At least some time during delivery an email message depends on open source. The open source community offers several robust solutions for email. Such solutions are especially popular for Web-based email. The most popular solutions are sendmail and Postfix, and many organizations rely on Majordomo for mailing lists.
Security and firewalls
Virtually all school networks are accessible from the Internet, so firewalls are critical. Unauthorized users and data must be kept out. Many schools enjoy considerable bandwidth which goes largely unmonitored overnight or on weekends. These so-called "fat pipes" are attractive tools for hackers trying to launch Distributed Denial of Service attacks or other mischief. Even some authorized users may try to bypass security (e.g. student "hackers").
Any security depends on thoughtful deployment and careful maintenance. Open source offers security programs with reputations comparable to or better than proprietary alternatives. OpenLDAP manages user authentication and IPCop is a robust firewall ("the bad packets stop here"). It's possible to create virtual private networks (VPNs) using open source software. The community offers a variety of tools to monitor and maintain networks. Since open source is modular and can be customized, schools can tailor the best solution for their needs.
DNS
Some schools or districts want or need software for DNS (Domain Name System). Such software is necessary to use the Internet. (It translates a text address like "www.yahoo.com" into an IP address like "216.32.74.51.") BIND (Berkeley Internet Name Domain) is a popular open source DNS.
Web proxy cache and Web filtering
Web sites generally load faster from a local proxy cache, so schools should create or subscribe to a Web proxy. Squid is a popular open source solution for Web proxy cache.
Schools may want to filter Web access, especially for students. SquidGuard and Dan's Guardian are popular open source Web filtering solutions. Current users praise the independence and control they have with an open source filtering solution. They can combine or modify blacklists of inappropriate sites or content, and share their lists and rules with other educators.
Databases
Most proprietary databases can run on Linux (e.g. Oracle, DB2). The most popular open source database is MySQL, especially as part of a LAMP solution: Linux, Apache, MySQL, and PHP/Perl.
Open Options is a product of the Northwest Regional Educational Laboratory. These materials are in the public domain and may be reproduced without permission. The following acknowledgment is requested on materials which are reproduced: Developed by the Northwest Regional Educational Laboratory, Portland, Oregon.
This Web site was developed and maintained by the Northwest Educational Technology Consortium. The federal funding for the regional technology consortia program ended on September 30, 2005, and no further updates are planned unless additional funding becomes available. However, much of the content is still useful and NWREL will continue to provide access to this site to support educators and to meet its own technical assistance needs.
![[Print]](../images/gif/print.gif "Print"){kind=small}