Listner LunaHa1o writes:

Instant Messaging (IM) is a great way to communicate with people… here is a breakdown of networks and clients.

Networks:

• AIM - This network is based of the AOL messaging network. This is by far the most network that is used by users.
• MSN - This network is based on the Microsoft messaging network. It requires a .net passport to login. If you have a @hotmail or @msn email address you can use that as your login. This is probably the second most used network.
• Yahoo - The Yahoo network is not as widely used anymore, but used to be one of the best networks to connect to. They have since decided to not release updates to their client (see below). Yahoo continues to patch their network in order to not let 3rd party clients connect to the Yahoo network.
• IRC - I will not spend much time on this as it is an advanced network for beginners. Please check back for a wiki entry on mIRC client to connect to the IRC network.
• ICQ - This network is the original AOL network and is still widely used by somewhat underground groups. This network has been known now as a hazardous network to connect to due to crackers using faults in the network to take advantage of others.
• Jabber - One of the least popular networks out there. Jabber is probably the most promising network as it is open source based. Jabber will most likely replace the more popular networks as it allows for much wider range of features and is of course free to connect to.

Clients:

“You may not reproduce, copy, or redistribute the design or layout of this website, individual elements of the website design, or our logos without our express written permission”, quoted from: http://www.aol.com/copyright/permission.html AIM - This is the standalone client from AOL. Recently some features have been moved to a pay only catagory. Eventually everything but basic chat will require a pay subscription. This is the most used client because people honestly don’t know any better.

See: “16. COPYRIGHT AND TRADEMARK NOTICES; OTHER ACKNOWLEDGEMENTS” @ http://privacy.msn.com/tou/ MSN Messenger - This client set the bar a little higher by offering some features a different way. These include a different way to send files and picture as well as talk and chat options. This client is the most used MSN client, but then again there are much better options available. MSN will also be a pay subscription soon for advanced features as those mentioned.

See: “http://docs.yahoo.com/info/copyright/guidelines.html” Yahoo Messenger - I’m not sure how widely used this is any more. Most have switched either to another network or use the Yahoo network with another client such as Trillian. This client used to be the most feature rich, but has since been surpassed by the basic MSN and AIM clients.

Trillian - The pay version is Trillian Pro. This is a one time fee that includes updates. Most users have heard of Trillian as a better client but they are scared to leave the basic clients such as MSN and AIM. Trillian honestly may be a bit to much for some users as there are a plethora of features. Trillian will also metaconnect. This means that it connects to all of the clients. (AIM, MSN, Yahoo (with patches), ICQ, IRC) You can get the free version but paid is worth the money!

MirandaIM - MirandaIM is an up and coming client. The feature list looks very promising. As of late, this client has been improving a great deal. Keep an eye out on this outstanding client.

“You must obtain permission from those owners before copying or using their trademarks, product names, company names or logos”, quoted from: http://www.qnext.com/legal_tc.html
Qnext - Wow. The file transfer and picture sharing are wonderful. Qnext actually has a feature called “zones” that allow users to easily share files and pictures with the person they are talking to. Setup is somewhat difficult if you are not familiar with setup wizards. If you read the instructions in the wizard it will help you greatly. Keep an eye on this client.

GAIM - This client is probably the best as of now. GAIM has a similar look and feel as iChat for OS X on the Mac. For people that do not like iChat-like interface and look this can be changed. As with Trillian, GAIM allows for plugins/extensions. Download GAIM and try it today. You’ll love it. GAIM is also a metaclient as it connects to a ton of networks. Please refer to the site for download and more info.

Added by Kalic:
IM2 - For most of the IM users, this is another all-in-one, a multi-IM client like Trillian. But it’s free. The GUI is similar to Trillian, skinable too. Supports AOL, ICQ, MSN, IRC and Yahoo networks. Currently it’s version 1.4 and still under vigorous development.