IN THIS CHAPTER
So far we have talked a lot about Linux being network-aware. Perhaps the main benefit of computer networking is to advance the ability of humans to network. When humans work together, amazing things get done. SUSE Linux includes a multitude of tools to help you work with other people, whether your collaborators are on the other side of your office or on the other side of the planet.
Several types of collaboration tools are included in SUSE Linux, but you can break them down into two groups:
Asynchronous communication—Mailing lists, Wikis, and Usenet news
Real-time communication—Internet Relay Chat, instant messaging, and video conferencing
The advantage of asynchronous (that is, the people involved appear at different times to participate) communication is that it shrinks the physical distance between participants. People do not have to be in the same room at the same time to get things done. Someone in New York can post a message on a global mailing list or newsgroup, and some hours later someone in Bangladesh, who was sleeping when the New Yorker posted, can respond.
The advantage of real-time communication is that it shrinks the response time. With everyone (virtually, at least) in the same room at the same time, questions can get answered instantaneously.
In this chapter, you will learn about all these methods. We covered the basics of email in the previous chapter, so you know how electronic mailing lists work from the user’s end, but that’s not all there is to know. SUSE Linux has two packages that will manage your own mailing lists: Majordomo and Mailman.
Usenet newsgroups have been part of the fabric of the Internet nearly as long as email and took hold well before the World Wide Web was invented. Although Usenet now has an even bigger problem with spam and malware than email, there remain thriving and helpful communities of Usenet readers and writers that can help you get answers to a multitude of questions for the price of a well-crafted question. Tap into Usenet with one of the news-reading tools discussed here, and then consider hosting your own NNTP server.
More recently, a new collaborative information tool has arisen on the Web. Wikis, short for WikiWiki Web, are web pages that any registered user can edit. Wikis can be places for sharing knowledge and brainstorming ideas, within your team or with your audience. You’ll learn more about creating your own wiki pages in this chapter, too.
Real-time communication tools have moved from the realm of teenage time wasters into serious collaboration tools for business. Chat and instant messaging technologies are now used to provide technical support for computer problems, confirm whether marketing and development are in agreement about a product, and even engage in complex business conversations and planning. In this chapter, you’ll learn about the variety of Linux tools you can use to engage in this activity.
Do you need to discuss some issues face-to-face with an important out-of-town client? It is no longer necessary to hop on an airplane with an expensive last-minute reservation. Arrange a videoconference instead. Both GNOME and KDE have tools to bridge the gap.
When Usenet began, it was a genuinely new way for Internet pioneers to collaborate with each other. Instead of having to use hit-and-miss methods of finding electronic mailing lists of interest and import to your work, you could set up a server for public bulletin boards where everyone interested in some topic could drop in, find out the latest information (or “news”) about that topic, and drop out again. Anyone who had news could post it there for everyone else’s use. People could ask questions and get expert answers, from real people. No one was obligated to read every message, nor would irrelevant postings begin to clutter one’s mailbox (at a time when disk space was at a premium). What could be better?
For a long time, nothing could. Newsgroups were created on most topics imaginable, organized hierarchically under a few basic categories: Computers (comp), Recreation (rec), Natural Science (sci), Society and Culture (soc), Debate and Controversy (talk), Miscellaneous (misc), and Usenet itself (news).
Anyone could propose to create a new group in these hierarchies, and there are democratic procedures in which users vote to approve new groups. This procedure grew oppressive for some people, leading to the rise of the Alternative (alt) hierarchy, where anyone could start a group, and many did (witness the existence of the alt.swedishchef.bork.bork.bork group).
Other hierarchies developed as hardware and software companies delivered Usenet support channels; colleges and universities set up internal newsgroups for students and faculty; and enterprising community-oriented geeks set up newsgroups for their local communities. Some are still functioning today.
Spam first raised its ugly head on Usenet when a pair of immigration attorneys posted an ad for their services in every newsgroup then active. Before the millennium arrived, spam had almost completely obliterated real postings on many groups. But many others are still quite useful.
Chances are good that your ISP offers at least some form of Usenet access. Contact them to find out the address of their Usenet server and the newsgroups they offer (also called their newsfeed). Many ISPs are selective in the content of their feed, especially when it comes to the alt groups. These are often seen as the seedier virtual neighborhoods, with pirated software, malware, and less-than-family-friendly text and images abounding. If there is a particular group you’re looking for, and it’s not included, it can often be added on request.
There are a few public news servers available, and you can find a list of them at http://freenews.maxbaud.net. Unfortunately, spammers often take advantage of this opportunity to peddle their wares, so be careful when using this.
Using Google Groups
Once upon a time, there was DejaNews, the Usenet archive, and it was good. Virtually every Usenet posting going back to the 1980s was included in this free web resource. Then the dot-com era collapsed and DejaNews was endangered. But who should come to the rescue, but the company working so hard to make the Web more useful to humans: Google.
Still technically in beta at this writing, Google Groups is both a way to search through the Usenet archives with all the standard Google search tools and get spam-free web access to all of today’s Usenet as well. Google does, of course, place ads on the pages.
Just go to Google Groups (http://groups-beta.google.com) and do a keyword search, or browse groups through the links. With free registration, you can subscribe to favorite groups and create your own public or private Google groups. Figure 16.1 shows the alt.os.linux.suse group in Konqueror.
When reading Usenet postings, your client makes it easy to respond, either by email or as a public follow-up posting. Some clients support multiple “identities” for posting and emailing, so you can choose a different signature or return address.
Caution
Spammers use software “bots” to collect every email address they find on Usenet, so never post a real email address. Use something that a human can read, but a bot would have trouble with, like [email protected].
Choices abound in reading Usenet in SUSE Linux. Many email clients can also deliver news. Several standalone clients are also around (Knode/Kontact, Pan, and several text-based choices). Some require you to be online when accessing news, others permit offline reading. Of course, there’s also gnus for Emacs.
Reading email and reading news are very similar tasks: Read and respond, perhaps save for later use. For this reason, the easiest way to keep up may be to use a mail client that supports reading Usenet.
Many email clients do this, including some of the best known: Mozilla Mail/Thunderbird, Evolution, Sylpheed, mutt, and pine. Setting them up to read Usenet is usually just a matter of identifying the Usenet server (often news.<ISPname>.com) and including login information, if authentication is required.
Reading news in a mail client is usually a plain-vanilla experience, without some of the fancier filters used by a standalone news client, but threads are usually supported (if they are supported in mail) and responding to a post operates the same way as email.
Support for binary transfers via Usenet, including images, multimedia files, and programs, tends to be a mixed bag. The yEnc encoding format is much more widespread in Usenet (see Chapter 15, “Managing Email Servers,” for more on yEnc), and if your email client doesn’t support it, you’ll miss out. As many viruses spread via Usenet binaries, this can be a good thing.
Maybe your email client doesn’t do news (for example, KMail), or you want something better adapted to the Usenet atmosphere (good binary transfer, bozo filters, and better ways to clear spam). Standalone newsreaders can be a good choice.
As with so many other GUI packages, there are standalone newsreaders for both KDE (KNode) and GNOME (Pan). You can include KNode inside Kontact if you want.
Pan runs much like the Windows newsreader Forté Free Agent, but is more advanced. You can read feeds from multiple servers, including the Novell Linux support groups (see Figure 16.2).
Figure 16.2. Pan is an easy-to-use graphical newsreader that was designed for GNOME but runs everywhere. You can choose to display groups, headers, and messages in a tri-pane format, as shown in this figure, or in tabs, with one pane showing and the others in the background.
Pan supports offline reading, so you don’t have to tie up your phone line to read news. This is a multistep process, but one that is easy to get used to.
Download headers for the group(s) you’re interested in. The headers include (among other things) the subject lines for the postings, who posted, and how long a message is.
Select the thread(s) in the group that you want to read.
Download the message bodies and go offline (press L or go to File, Work Offline).
When you want to post a message, either by email or to the group, Pan gives you the choice to Send Now (if you’re online) or Send Later (for offline use). The Send Later option is also good if you’ve just composed a really nasty flame and want time to reconsider. When you go back online, go to Post, Send Queued Messages to finish.
Tip
Pan messages marked Send Later are queued in the pan.sendlater folder. To edit or delete a message, choose Folders from the Show Groups pane. Select pan.sendlater and you should see your message in the Headers pane.
Pan has excellent support for Usenet binaries and plays nicely with yEnc. The filters are a little difficult for an ordinary person to decipher, and there is no manual or online help. A team was working on a manual as of this writing.
KNode, although not identical to KMail, functions very much like it. As the only part of the Kontact suite not turned on by default, it might be considered something of a weakling; instead it is a fairly muscular client.
Figure 16.3 shows how to configure KNode to receive the official Novell support newsgroups, including the SUSE Linux and Ximian application groups.
Figure 16.3. Configuring KNode for the Novell Support forums. News client server configuration screens are very similar to each other.
Tip
There’s an even easier way to subscribe to the Novell support groups: Open http://support.novell.com/forums/2su.html in Konqueror. Click any of the NNTP links on this page, and you’ll be asked if you want to follow this link. Click Follow. KDE will open KNode automatically and download the current articles in the selected newsgroup.
Now click the up arrow in Konqueror, and you’ll be taken to the main newsgroup page to subscribe to more groups!
Setting up a client to read a particular news server is not hard. Generally all you need is the server name and know whether you need to supply a password (that is, be authenticated) before using it. Some news servers are public, allowing anyone to connect, but most require some identification. By default, news servers use Port 119 to communicate with clients. Like your mail client, if you expect to keep KNode open for awhile and want to check for new articles/postings periodically, you can set the interval here. If you mostly want to read news offline, you should not turn on the interval check.
KNode also lets you specify an identity to respond to newsgroup articles on a per-account basis. Click the Identity tab to enter in a name, an email address for the From line, and (if you want) a different address in the Reply To field. KNode will use the default settings if you don’t say otherwise.
Although not hopeless, KNode works better with text files than with binaries. KNode displays images and supports yEnc. Filters are easier to create than in Pan, especially if you have created filters in KMail.
Go to Settings, Configure KNode, Reading News. Click the Filters tab and you’ll see the default filters. Suppose you post questions to Usenet, and you just want to see the follow-up articles to your question. To do this, click New and follow these steps:
Name the filter
Follow ups to my questions. Make sure the Show in Menu box is checked so you can apply the filter easily.Click the drop-down menu to change the Apply On setting to Whole Threads. Leave the Subject area as is.
Go down to the From area and type the placeholder variable
%MYNAMEinto the box. The filter will then look for articles with your name, as defined in the Identities settings.Click the Status tab and check the Has New Followups box, and then change the setting to True using the drop-down menu. Click OK to create the filter.
Now go to View, Filter (or click the Filter toolbar icon, which looks like a funnel), and select Has New_Followups to activate your filter on the current group.
Because there was Usenet almost before there were GUIs, many text-based newsreaders are still in use. Some are even under active development. Included with SUSE Linux are NetNews (nn), InterNetNews (inn), tin, slrn, and suck.
Before starting any of these, you need to set your news server as an environment variable. Do this as user, not as root. From the shell, type the following:
export NNTPSERVER=<YourNewsServerDomainName>
The next step is to view the groups on your server and subscribe to one or more. This is done by creating a .newsrc file. As an example, let’s use slrn. Type the following:
slrn -f .jnewsrc – create
This configuration file, located at /etc/slrn.rc, is well commented and easy to customize.
When you create the .newsrc file, and, if necessary, log in, slrn will get all the groups available on the server. To subscribe to an interesting group, select it from the list and type a capital S. To just see your subscribed groups, type a capital L, followed by the Esc key, and then the number 1.
Figure 16.4 shows slrn in action.
The WikiWikiWeb, taken from the Hawaiian expression for fast, quick, or speedy, was created by Ward Christopher as a way of tapping into the collective knowledge of his circle of friends and co-workers. It combines features of email lists, software documentation tools, and the simple structure of the Web to generate useful, accessible, and frequently updated and reviewed information.
The idea caught on, and people are collaborating with Wikis in all sorts of ways. The best known example of a successful and popular Wiki is Wikipedia.org. Its goal is to produce a basic compendium of human knowledge about most anything. As of February 2005, the English version of Wikipedia was approaching 500,000 articles produced, with at least some articles in some 20 other languages. It has spawned other projects, including WikiQuotes, the Wiktionary, and the Wikinews citizen journalism project.
Dozens of packages have been written to create Wikis with. These packages, called WikiEngines, have varying features. Like blog software, one WikiEngine should meet your needs and idiosyncrasies. Wikipedia uses the MediaWiki engine. SUSE Linux comes with one engine, the Zope-based ZWiki engine. Other engines are easy to get, with varying degrees of installation difficulty. See http://c2.com/cgi/wiki?ChoosingaWiki for help in selecting a package.
This package builds Wiki functioning on the Zope web application server package. Zope (the Z Object Publishing Environment) was built as an object-oriented tool for creating dynamic websites. It includes a content management framework, its own relational database (and works with other database management systems) and other publishing tools. It is written mostly in the Python scripting language.
Getting ZWiki up and running is a two-step process because you need Zope first. Get Zope installed via YaST, and then go to the Runlevel Editor in YaST (see Chapter 22, “Managing the Boot Process and Other Services,” for more information on the Runlevel Editor) to turn on Zope.
Download the latest ZWiki version from http://zwiki.org. New versions are generally released once a month. Extract the tarball to /var/opt/zope/default/Products and then reboot the system to launch Zope.
Open a web browser to http://localhost:8080, and you should see the Zope welcome message. Click the link for the Zope Management Interface. You’ll be asked for a username and password. The SUSE Engineers have created a default user, which is the information you should use the first time. Username: superuser, Password: 123.
From the main screen, use the Select Type to Add drop-down menu to Add ZWiki. Click Add. Figure 16.5 appears.
Give an ID name for the ZMI and a title for your Wiki. Click Create Wiki (and Enter). You’ll see the default page in the default skin (see Figure 16.6).
Click the Edit link to replace the default text with your own (see Figure 16.7).
Note
Learn more about Zope in Chapter 26, “Managing Your Apache Web Server.”
ZWiki is flexible in the types of text you can input. It can read and interpret standard HTML, Zope’s Document Template Markup Language (DTML), StructuredText (Zope’s attempt to simplify the XML documentation standard DocBook for engineers), and standard WikiWikiWeb markup. The latter, which creates a page link for all words with capitals placed inside the word (like WikiWikiWeb or WhyWikiWorks), can be simultaneously very cool and very frustrating.
Note
As was mentioned earlier, ZWiki was discussed only because it ships with SUSE Linux. Many other packages/WikiEngines are available and you will want to use the one that best meets your needs. Visit http://c2.com/cgi/wiki?ChoosingaWiki to select a package for your implementation if you want to use something other than ZWiki.
Mailing lists are a traditional method of asynchronous electronic collaboration. They require no special skills or text formatting abilities from the user, and can serve loads ranging from a small workgroup on a specific project to a global membership of thousands, even millions, of people interested in discussing the World Cup every four years. They are easy to administer, especially if the membership does not change much over time, and can help a website owner draw traffic with a touch of community.
The concept of an automated list is pretty simple: a list is an organized discussion among a group of people. To initiate a discussion (or thread), you can send a single message to the list management software, which then reflects the message to all list subscribers; that is, the people interested in the discussion.
Over the years, there have been several list management tools in use: L-Soft’s Listserv, majordomo, and Lyris, to name some of the best known. Recently, an open source package called Mailman has pulled an increasing share of the traffic.
For users, Mailman provides a consistent, web-based interface for managing their own participation, including subscribing/unsubscribing, getting a daily digest of postings, accessing the list archives, turning off the list for vacations, and so on. List administrators get many automated tools that make their jobs easier and less time consuming. Mailman is one of two list-management tools included in SUSE Linux (the other is majordomo).
Mailman keeps track of all subscribers and watches for (and deals with) bouncing messages to some subscribers. It also generates the list archives, if the administrator asks it to.
There is always at least one administrator or moderator for any list—perhaps that is you. That person has access to a special, password-protected administrative web page; there, you can perform your list-god duties, such as
Manually adding or deleting members, either because you’re a nice person or your hand has been forced.
Writing a Welcome message for new list members with the list ground rules.
Setting the level of moderation for the list: Do you want to inspect every incoming message, or maybe just a new person’s first few postings to certify they’re not a spammer in disguise.
Removing offensive messages from the archives.
YaST does most of the installation tasks, but there are a few configuration steps you must take before you can create a new list on your own system. These steps are explained in the /usr/share/doc/packages/mailman/README.SuSE file. The SUSE team assumes you are using Postfix as your MTA (see Chapter 15) and Apache as your web server (see Chapter 26).
In YaST’s sysconfig editor (under System), go to Network, Mail, Mailman. (You can also edit
/etc/sysconfig/mailmandirectly.) Identify the following items:MAILMAN_SMTPHOSTMAILMAN_DEFAULT_NNTP_HOSTMAILMAN_DEFAULT_EMAIL_HOSTMAILMAN_DEFAULT_URL_HOSTMAILMAN_VIRTUAL_HOSTSand run
SuSEconfig -module mailman.
Call
/usr/lib/mailman/bin/mmsitepassas user root to set your site master password.As root, edit
/etc/postfix/main.cf. At the bottom of the file, you will see that YaST has already configured a default alias map:alias_maps = hash:/etc/aliases, ...,Add this statement to the line:
hash:/var/lib/mailman/data/aliases.Return to the root shell and reload postfix with this command:
postfix reload.Finally, call
/usr/lib/mailman/bin/newlist mailmanas user root to create the master mailing list. This list is needed for the inner workings of Mailman. You will be asked to set up a password as the site administrator; make it easy to remember, but relatively hard to guess.
Now you can use the web interface to set up your list.
Tip
Need a host for your Mailman list? You can find a directory of free and commercial hosts at the Python-friendly Web Hosting page: http://www.python.org/moin/PythonHosting. Look for Mailman in the Services Offered column.
Mailman files are stored in /usr/lib/mailman/bin. They are owned by root, but all members of the Mailman group have execute rights and can run Mailman commands, using either the web interface or from the shell.
Open your browser to http://localhost/admin to see the Mailman web interface. Now you can create and administer lists.
To run Mailman shell commands, change directories to /usr/lib/mailman/bin and then run your command. For example, to create a new list, type the following:
./newlist
The dot-slash is there because the commands are purposely left out of your path for security reasons.
When you create a new list, you’ll be prompted to name the list (use all lowercase letters) and give the email address of the list owner. Mailman will send a confirming email to the owner you name. You establish the initial list password in this sequence as well.
You can find the documentation for Mailman in /usr/share/doc/packages/mailman. You’ll find README files that cover potential problems with various mail transfer agents and operating systems and the current Frequently Asked Questions list. More formal documentation, tailored to different types of users, is at http://www.gnu.org/software/mailman/docs.html. You can read this online or download the PDF or plain-text versions.
Real-time electronic communication takes two basic forms: Internet Relay Chat (IRC) is like live Usenet, where you go to a group (called a channel) and discuss a topic identified by that channel. Anyone can establish a channel, invite users to participate, set ground rules, and kick users out if they break the rules. Everyone on IRC has a “handle” used to identify them in the chat. Things are relatively anonymous.
Instant Messaging (IM) is a one-on-one process where users can chat with each other without having to visit an IRC channel. Popularized by America Online’s Instant Messenger, several networks have since risen to facilitate instant messaging across the Net.
SUSE Linux users can choose from several clients to handle their real-time communication needs, both IRC and IM.
Like email, the IRC protocol is fundamentally about text. The first IRC clients were based on the command line, and many of these are still in use. But just as plain-text email morphed into HTML-based mail with file attachments and GUI clients, so has IRC.
SUSE Linux includes these IRC clients: Ksirc is the default KDE client (although Kopete works with both IM and IRC networks). Xchat is the X Windows standard IRC client. Kvirc is another KDE-based client, and tkirc is a command-line client based on the tcl-tk language. If you don’t already have a favorite, try them all.
Caution
For security reasons, never run an IRC client as Root. For the most secure IRC experience, create a special IRC user and always launch your client as that user.
When encountering IRC for the first time, it can be a little intimidating. Unless you know exactly where you’re going (as when someone invites you to a specific channel on a particular network), you have a multitude of choices.
Your first choice is the network server. Each client offers a wealth of public IRC servers to connect to (Kopete lists 49 in its wizard; Xchat lists 73). The default lists included with your client can be edited. EFNet is the oldest IRC network, but there are many popular IRC networks, including DALNet and Undernet. Depending on the client, you can connect to multiple servers simultaneously to participate in different channels. If you are looking for Linux support, check out ChatJunkiesNet.
Each server hosts multiple channels/rooms. These are topic areas and can vary constantly. Some channels are always present on a network; others are there only when something is scheduled. You can search the channel list for a topic (especially useful in one of the popular networks, because tens of thousands of channels may be open at any given moment). The list will tell you how many people are logged in on that channel at that moment and give you a description of what the channel is about. You can get a sense of the channel’s conversational tone by the description. New users should probably stay away from channels that announce that “Lamers will be SHOT.” Most channels are public, but you can set up private channels that require a password. This is configurable in your client.
After you have selected a channel, you can jump right in to the conversation. As you can see in Figure 16.8, the client should display a list of the participants’ nicknames in one window, and postings will appear as scrolling text. Introduce yourself, ask a question, or just say “Hi!”
Figure 16.8. An IRC channel window. Postings scroll down in the upper-left pane, and participants are listed in the upper right. Post your message in the bottom editor.
Note
IRC can be a pretty nasty environment. Given the relative anonymity of its participants, things can happen here that are not rated PG. Language can be crude and folks can be in chat rooms for every reason imaginable. You may want to watch out if someone starts a conversation asking for your “a/s/l” (age, sex, location). Visit http://www.irc.org/fun_docs/nocuss.html for a humorous take on the language issue, with a few tips on IRC netiquette.
When in IRC, the Golden Rule applies very well. Be respectful to other chatters, don’t write in flashing ALL CAPS (even if you want to show off all the things your client can do), and ignore the idiots who act inappropriately.
Instant messaging should be much simpler than IRC, and it can be. The central problem is the multitude of proprietary IM protocols. The three dominant players—AOL Instant Messenger/ICQ, MSN Messenger, and Yahoo Messenger—all use different methods to connect users of each of their clients.
As long as you and everyone else you want to IM are on the same network, all you need is one account. If you have one friend on a different network, you have to get another account, possibly with another username or password to configure.
You have two ways to solve this dilemma: get a single IM client that supports all the protocols or have all your friends adopt the open-source Jabber protocol and use a Jabber client.
Kopete and GAIM (for KDE and GNOME, respectively) are multiprotocol instant messengers that can run all the previously mentioned systems and leave you active for hours on end. SIM (the simple instant messenger) is an ICQ-only client (as is the command-line licq).
The GAIM configuration window in Figure 16.9 shows the protocol choices you have.
Jabber is designed to be a universal web-standard IM protocol. Someday the others should all adopt it, but that won’t happen soon. If more people used Jabber clients, the day might be hastened. In addition to Kopete and GAIM, KDE has the PSI Jabber client, and GNOME has Gabber.
GnomeMeeting allows Linux users to participate in phone conversations and video conferences from any sufficiently equipped PC with an Internet connection. It uses the H.323 voice-over-IP (VoIP) protocol to transmit voice and (if available) webcam video to and from your location. GnomeMeeting will run on dial-up and broadband connections, although the video will be more troublesome on a slow connection.
You need a working full-duplex-capable sound card, a microphone, a webcam, and a video device to take advantage of all GnomeMeeting’s capabilities. If you just want to listen in, the sound card is all you need.
The first time you run GnomeMeeting, a wizard appears that will configure your system. Enter your name, email address, and location, and select your connection type. GnomeMeeting should detect your audio and video devices, and away you go.
When you run GnomeMeeting, you must register with an ILS Directory server to make and receive calls. By default, GnomeMeeting uses the server at http://ils.seconix.com; you can configure a different server if you want. This will put you in the user directory and make you accessible to the world. Tell the people you want to connect with using GnomeMeeting to register with the server as well so you can call them.
Tip
The Skype Voice-over-IP (VoIP) service also works with SUSE Linux. Download the SUSE RPM from http://www.skype.com/go/getskype-linux-qt32.
http://groups.google.com—Google Groups. Read Usenet on the Web and create groups of your own.
http://www.isc.org/index.pl?/products/inn—The InterNetNews Usenet server and reader.
http://slrn.sourceforge.net—“s-lang read news”; the slrn newsreader.
http://knode.sourceforge.net—KNode newsreader in Kontact and KDE.
http://pan.rebelbase.com—The Pan newsreader for GNOME.
http://c2.com/cgi/wiki?WikiWikiWeb—WikiWikiWeb, Ward Cunningham’s original collaborative site.
http://c2.com/cgi/wiki?ChoosingaWiki—Choosing a WikiEngine, with help from Ward Cunningham’s assembled masses.
http://zwiki.org—ZWiki, the Zope-based wiki engine included in SUSE Linux. Docs still in progress.
http://zopewiki.org/ZopeAndApache—Getting Zope and Apache working together. Helpful when hosting ZWiki on Apache.
http://twiki.org—Another popular Wiki engine.
http://en.wikipedia.org—The Wikipedia home page, perhaps the best example of how wikis work.
http://www.list.org—Home of the Mailman list manager.
http://www.greatcircle.com/majordomo—The Majordomo list manager.
http://www.siliconexus.com/MajorCool—The web interface for Majordomo.
http://www.irchelp.org—The place to get help with Internet Relay Chat.
http://www.irc.org/links.html—IRC clients, channels, networks, and bots. Find them here.
http://tldp.org/HOWTO/IRC—The Linux IRC mini-HOWTO.
http://kopete.kde.org—Kopete, the KDE instant messenger and IRC client.
http://www.jabber.org/user/userguide—The Jabber user guide, for learning about this open-source IM protocol. Jabber.org also hosts a public IM server for you to connect with.
http://gabber.sourceforge.net—The GNOME Jabber client.
http://xchat.org—The Xchat home page.
http://www.licq.org—LICQ, the mother of all Linux instant messengers.
http://gaim.sourceforge.net—This IM client started as an AOL Instant Messenger (AIM) clone, but now supports most other IM networks as well.
http://www.gnomemeeting.org—GnomeMeeting videoconferencing home page.