IRC, or Internet Relay Chat, is a fairly old communication method and is especially popular within open source project communities. Zabbix users also like to gather for Zabbix-related discussions on a dedicated channel. Located on the Freenode network at freenode.net, the #zabbix channel is where you can expect to get help from, and communicate with, fellow Zabbix users.

The most advanced and knowledgeable community members can be found here. You may use one of the many web-IRC gateways, such as http://webchat.freenode.net/, or connect to any Freenode IRC server with a dedicated program called an IRC client. There are many different options available for different operating systems, and you are free to choose any one—it won't impact your ability to communicate with people using a different one. In addition to general communication guidelines, there are some IRC-specific ones as well:

• To reiterate the basic suggestion: be patient. Too often, people come in, ask their question, and leave a few minutes later. Other members of the channel might be sleeping, eating, or otherwise away from their computer. So ask your question and stay around for a while. If it happens to be a weekend, a while might even be several days.
• Don't ask whether you can ask you question. If it's about Zabbix, and is well thought out, just go ahead and ask. Starting with, Hey, can I ask a question about Zabbix? will require somebody to confirm with, Yes, you can, then you typing the question, and only then can the helping process start, which will take much longer.
• Don't repeat your question too often; it will only annoy others. While it might be tempting to ask again and again when new people join, they are unlikely to be the experts you are waiting for, so again, be patient. On the other hand, it usually is fine to repeat the question if no answer has appeared for a longer time—a day, for example.
• Don't type the names of people present, hoping it will get you help. That will needlessly distract them. Wait for somebody to respond instead.

Regarding politeness, remember that all communication is logged and publicly available. If you reveal yourself to be a person who is hard to communicate with, it will not only stay in people's memories, but also in the logs.

The Zabbix IRC channel also has a couple of automated helpers, called bots. All new bug reports and feature requests are announced in the channel by them, and they have other features as well. At this time, current bot features are described at http://zabbix.org/wiki/Getting_help#IRC_bots.

Not only the most knowledgeable users are available on the Zabbix IRC channel. This channel is quite popular. At the time of writing, the average number of participants is about 300. It's actually the most popular IRC channel about monitoring. The demo Zabbix instance, at http://zabbix.org/zabbix/, monitors the number of users on the channel, and a graph from 2006 until mid-2016 looks like this:(at time of writing the demo site was down so it was not possible to update the graph with newer statistics)

The number of participants on the channel has grown significantly since 2006. You can access the current version by going to http://zabbix.org/zabbix/ and looking up the simple graph Users in #zabbix on freenode on the Zabbix.org host.