This guide will show you how to set up an XMPP account and use it. I'll be using a windows program, but it's basically the same no matter what you use. I'll also cover OTR (Off The Record), which is used to encrypt your messages. I'm not going to go into the details of how XMPP works. Besides, there are many other tutorials out there for this that are exactly the same, so I'm just going to make this brief. You send a message, it goes to a server, the server sends it to the recipient. Simple. Much like email.
To start off we are going to need the xmpp client, Pidgin. And we need to download the OTR plugin for it as well. For pidgin, you need to go to this address here, and choose the newest version. (The top folder) Then download the file that ends with offline.exe. There is an online installer as well, but sometimes it doesn't work correctly. Next we need to download the otr plugin, you can find this download at the bottom of the main website. If you've read my previous post on using PGP, you'll notices there's a signature here (.asc) you can use to ensure validity of your download.
Now that you have them downloaded we can begin. Just double click the Pidgin setup. You can leave everything to defaults if you want, or you can add different localization for other languages if you need them. You can change the install folder if you need to, but if you do you'll have to change it in OTR as well. Once you have pidgin installed, it should run automatically. If not, go to your start menu and open it.
Once Pidgin opens it will ask you to add an account. We don't have one yet, so this is where we will create one. First change the protocol from AIM to XMPP. Now you'll see the rest of the options we need.
For the username, choose whatever you wish. If it's already taken it will let you know when you try to register. For domain, this is the server you are creating your account on. (Like gmail or yahoo on email.) There are tons of jabber (XMPP) servers online, so just google them until you find one you like. A few I'd recommend are hacker.im, jabber.calyxinstitute.org, and creep.im. You want one that doesn't keep logs, and isn't a closed system. A closed system is one that can't communicate with other ones. For example, if gmail was a closed system you would only be able to message other gmail users. Not aol or yahoo. For resource, this is a way of saying which of your devices you are using. A way of seperating your phone/laptop login from your desktop login. Next of course is your password, just follow strong password settings and you should be good here.
The rest of the options are either not required, or are already on the values they should be at. The only exception is if you use a proxy. If so, add this to the tab at the top labeled Proxy. Now you just need to tick the checkbox near the bottom saying to create the new account, then click add. A few servers will require you to make an account on their website instead of using the checkbox. But the majority of them will work this way.
Now you have an account and can message people. You can add buddies to your friends list and start chat in the top left. You can add a buddy icon in the bottom right. Change your mood/status in the bottom left. And change your settings/preferences at the top. The net thing we need to do is add OTR so that your chat's can be encrypted.
Okay, so now we need to install the otr plugin you downloaded earlier. Just double click it and let it install. You can keep everything default unless you've changed your Pidgin location.
Once it's installed, open pidgin and go to your plugins. (Tools -> Plugins) Scroll down to the off-the-record messaging plugin and tick the box to enable it. Now select it and press configure plugin. The next step is to generate your key. Select your account from the drop down list, then click generate. (Easy, right?) If you want, you can also tick the box to require encryption. If you have this ticked, you won't be able to message someone without using encryption.
You're not done just yet though. Whenever you start a chat with someone, you have to turn on OTR, it doesn't just automatically protect everything you type. Once you're in a chat, there will be a box in the top right. Either click the box or the menu that says OTR. In the dropdown box, click the button to start the private chat. Next you'll have to wait for the other person to join the private mode as well. Once it is done, you'll be asked to verify. Verifying is a way to make sure the person you are talking to isn't an impostor. Anyone can make an account with the name [email protected] To make sure you're talking to the right person, always send a verification code using something else. Preferably this is something encrypted that nobody else has access to. It's best to secretly exchange a key such as this in person, but online that's generally not possible.