While it's not as widely used as it once was, Sendmail continues to be a very popular mail transfer agent. Newer features include support for filters, authentication and external database look-ups. Operating System: Linux
This MTA was developed at the University of Cambridge and is still widely used in the UK. It's best for servers that are unlikely to have large volumes of mail because it doesn't have a central queue manager. Operating System: Linux, Unix
Based on CentOS and Red Hat Enterprise Linux, SME Server offers file and printer sharing, a mail server, network firewall, automatic backup, remote access and more. Installation and basic configuration take only about 20 minutes, and there's quite a bit of documentation for the project available on the site's wiki. Operating System: Linux
Although not as human-sounding as some other text readers, eSpeak provides clear audio of the text on your screen. It supports dozens of different languages, as well as several different English accents. Operating System: Windows, Linux, OS X.
If you'd like to be able to talk to your computer, check out Simon. It accepts voice commands and turns audio into text. Operating System: Windows, Linux
Formerly known as Wengo, this project enables free VoIP calls from one PC to another. This is still a developing project, so it's not as easy to use yet as Skype or some other VoIP solutions. Operating System: Windows, Linux, OS X
Originally developed by the World Wide Web Consortium (W3C) in 1996, Amaya promotes two-way Web communication by incorporating both a Web page viewer and a Web page editor. It supports multiple Web languages, including HTML, CSS, XML, XHTML, MathML and SVG. Operating System: Windows, Linux, OS X
First released this year, BlueGriffon uses Gecko, the same engine used by Mozilla products, so it makes it easy to see how your Web pages will look on Firefox. While the core software is free, several add-ons require a fee. Operating System: Windows, Linux, OS X
KompoZer aims to make it easy for novices to create Web pages thanks to an intuitive Web file management system and an excellent WYSIWYG editor. The interface is similar to Dreamweaver's, and like BlueGriffon, it's powered by the Gecko engine. Operating System: Windows, Linux, OS X
This "all-in-one Internet application suite" includes a Web browser, e-mail client, feed reader, chat client and HTML editor. It's powered by Mozilla source code, and has a large library of add-ons for more features. Operating System: Windows, Linux
For XML only, this editor is lightweight and fast. It validates your code as you type and offers a simple, basic interface. Operating System: Windows, Linux
This simple-to-use wiki was designed for developer teams and other small groups. Key features include unlimited revisions, recent changes viewing, section editing, anti-spam capabilities, multiple language support and more. Operating System: OS Independent
Because it's the software used by Wikipedia, MediaWiki should feel familiar to most users. It's scalability makes it a good choice for large wikis. Operating System: Windows, Linux/Unix, OS X
TikiWiki calls itself "Groupware" because it offers features like blogs, forums, an image gallery, map server, bug tracker and feed reader to standard wiki capabilities. The software is completely open source, but support, consulting, hosting and other services are available through third-party partners listed on the site. Operating System: OS Independent
One of the ways around the issues of security and control that make some businesses wary of cloud computing is to build a private cloud -- one that remains within the corporate firewall and is wholly controlled internally. Private clouds also increase the agility of IT an organization's IT infrastructure and make it easier to roll out new technology projects. Download this eBook to get the facts behind the private cloud and learn how your organization can get started.