shMessenger!

WhatsApp Messenger is a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for iPhone, BlackBerry, Android, Windows Phone and Nokia and yes, those phones can all message each other! Because WhatsApp Messenger uses the same internet data plan that you use for email and web browsing, there is no cost to message and stay in touch with your friends.

Facebook Messenger is a faster way to message. Reach friends right on their phones, get and send messages fast, message everyone at once and more.

Trillian is an instant messaging app that works on phones, tablets, and desktops while keeping your chats neatly synchronized between all of them! We think conversation should be easily shared between all of your devices, not trapped as text messages on your phone. Here's how we do it:• INSTANT MESSAGING: Your unique Trillian username can be used to send unlimited messages free of charge. Trillian uses your existing data plan and/or WiFi.• ANYWHERE: Trillian's continuous client feature delivers your chats instantly between all of your connected devices. In addition, Trillian automatically silences push notifications on mobile devices if you're active on a desktop - no more dealing with a phone buzzing on your desk all day!• SIMPLE: Trillian places a strong emphasis on fast and reliable message delivery and a beautiful, easy-to-use interface.• SECURE: All communication with Trillian servers uses TLS to ensure third-parties can't read your chats.• INTEROPERABLE: Of course, Trillian wouldn't be Trillian without support for Facebook Chat, MSN, Google Talk, AIM, ICQ, Yahoo!, and Jabber. »

Linphone is an internet phone or Voice Over IP phone (VoIP). With Linphone you can communicate freely with people over the internet, with voice, video, and text instant messaging. Linphone makes use of the SIP protocol, an open standard for internet telephony. You can use Linphone with any SIP VoIP operator.

See up to 8 friends on live video while chatting with them! Create your own room (appear.in/your-room) and send the link on chat, Facebook Messenger, SMS or email to invite people. No registration required, once people click the link, they'll appear with you!

Empathy is a messaging program which supports text, voice, video chat, and file transfers over many different protocols. You can tell it about your accounts on all those services and do all your chatting within one application.

Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].

The goal of Gajim is to provide a full featured and easy to use Jabber client. Gajim works nicely with GNOME, but does not require it to run. It is released under the GNU General Public License.

Digsby is a multiprotocol IM client that lets you chat with all your friends on AIM, MSN, Yahoo, ICQ, Google Talk, and Jabber with one simple to manage buddy list. Its also a social networking tool that alerts you of events like new messages and gives you a live Newsfeed of what your friends are up to on Facebook, Twitter, MySpace and more.

Yahoo! Messenger is an instant messaging client developed by Yahoo! inc. for real-time communication of its users. It provides text chat, file transfer up to 2GB. conversations with audio and video, games. It also supports International Calling, Phone in Number and sending free SMS like Skype.