Chapter 6 - Software Components

Edubuntu includes both Open source Educational Software as well as great office tools and web utilities (the section called “Applications”). At its core, however, it consists of the server software that runs the classroom server and the...

K12LTSP classroom server

About the K12LTSP distribution

Edubuntu's LTSP component is based on the K12LTSP distribution, with some configuration changes and additional software packages.

K12LTSP is based on the Fedora Project and the work of the LTSP. It's easy to install and configure. It's distributed under the GNU General Public License. That means it's free and based on Open Source software.

• LTSP is the Linux Terminal Server Project. This project assembles all the software components that are necessary for a computer to act as a fat server for a network of thin clients, and provides the configuration necessary for the server to function as such.
• The Fedora Project is a Linux distribution maintained by the developer community with contributions from Red Hat, Inc. The K12LTSP team has added an option to the Fedora installation menu, so that installing a classroom server is as simple as choosing the first installation option and answering some questions.

The K12LTSP distribution tries to make it as easy as possible for you. It is a regular Fedora distribution with an option to install LTSP right there in the setup screen. When installing, the LTSP option is the first item on the menu, added above the default Workstation, Server and Custom options. This means that you don't have to mess around with the configuration files until you've had a chance to see what it is they do, and by then you'll probably only need to tweak them a little.

The LTSP server defaults to an IP gateway and firewall when two ethernet cards are present. This will only be the case in Edubuntu that is configured to be permanently online, which will usually not be the case.

Mediawiki

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Mediawiki overview

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Wikipedia

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Applications

OpenOffice.org

OpenOffice.org is a full office suite, intended to measure up to and surpass Microsoft Office. This is what its original author, Marco Börries, intended when he started StarDivision to create the software that would eventually become OpenOffice.org in 1984, when he was just sixteen. He called it StarOffice. By the time Sun Microsystems bought Marco's company in 1999, over 25 million copies of Star Office had been sold to customers who needed platform independence (the section called “Glossary”) and an alternative to Microsoft.

In July 2000, Sun released most of the Star Office source code (about 7.5 million lines of C++) to the stewardship of the open source community, under the Free Software Foundation's LGPL license. The community project has as its goal: “To create, as a community, the leading international office suite that will run on all major platforms and provide access to all functionality and data through open-component based APIs and an XML-based file format”. The open APIs (the section called “Glossary”) and file formats are turning OpenOffice.org into a platform in its own right, supporting projects such as OpenGroupware, which aims to provide an open alternative to Microsoft's Exchange and SharePoint products.

This is in direct contrast to Microsoft's approach, who have always used the fact that only their own software could easily use their document formats to keep customers locked in, in effect reserving the Office platform to Windows applications.

OpenOffice.org includes a word processor, spreadsheet, interfaces to many databases, a presentation builder, and a diagramming tool. It is now able to decode most variants of Microsoft Office document formats, but although its StarBasic macro language is syntactically identical to Visual Basic, OpenOffice cannot execute Visual Basic scripts. Although these are preserved upon conversion, the scripts need to be adjusted to use the OpenOffice API before they can be used.

OpenOffice.org can be used to teach all the basic computer skills required to enter the job market, and as the design paradigms of the software is very close to Microsoft Office, the skills learnt are readily transferable.

The Mozilla Project

In 1998, Netscape Communications released the source code of its Navigator web browser software as open source, and the Mozilla project was born. Netscape released their software as open source in order to compete with Microsoft, who were bundling Internet Explorer with every copy of Windows sold. Netscape hoped that the cooperation of thousands of developers around the world would create a better product than Internet Explorer. It did, but it took years, and Netscape fell by the wayside. The code lived on, though.

In 2004, six years after the start of the project, the non-profit Mozilla Foundation that was created to coordinate the project finally released version 1.0 of the Mozilla Firefox web browser. Earlier versions of the software had been in use for years, but at last it was deemed ready for a high-profile release to the general public.

The full Mozilla suite includes far more than the web browser. It includes Mozilla Thunderbird, a mail client with address books and junk email filtering, Mozilla Sunbird, an integrated calendar application, and Mozilla Composer, a web page editor. For developers, it includes Venkman, a Javascript debugger, and the DOM Inspector, a wonderful tool for interactively exploring the enormous, intricate internal structure of complicated web pages.

The codebase has been painstakingly restructured to get as much use out of it as possible. So, for instance, all the Mozilla applications use the same rendering engine, called Gecko, to layout and display HTML pages on screen. This is critical, since it is extremely hard work to implement the standards that govern web page structure and display correctly. Mozilla has the best support for the HTML and CSS standards of any browser out there. In the past, Microsoft has used Internet Explorer's idiosyncratic and incomplete implementation of web standards to coerce people to craft their web pages to look good in Internet Explorer at the expense of other browsers. For the web to become a dependable platform, however, developers have to be able to build on solid public standards that don't leave them at the mercy of any company's prosperity.

As with OpenOffice.org, the Mozilla project is becoming a platform for extensions from the community. Security

As the Internet has become more popular, viruses, spam, spyware and trojans have grown to be an enormous problem. These are all caused by programs that are received and executed on computers without the knowledge or consent of their users. How can this happen?

In general, there are two ways for this to happen:

• You may have given implicit permission without intending to do so;
• The unwanted program may be exploiting errors or bugs in some program in order to insinuate themselves into it, so that it can execute with the permissions of the original program.

Mozilla Firefox and Thunderbird try to protect you as far as possible by setting up reasonable defaults. Nothing in an email message is executed unless you explicitly run it yourself. And execution of Javascript in web pages can be switched off at any point. Firefox also allows you to grant or revoke specific permissions (e.g. opening popups, hiding the status bar, or changing images) to Javascript.

The Mozilla suite also affords you a measure of protection from the second case. While Internet Explorer has access to practically the entire running system of a Windows PC via a powerful integration technology called ActiveX, Mozilla Firefox and Thunderbird are far more restricted. It also helps to be running on Edubuntu, where the user of the web browser will generally not be able to damage the operating system, and the system administration account is never used to run user applications.