Coccinella is described as 'Free and open-source cross-platform instant messaging client with a built-in whiteboard for improved collaboration with other people' and is a instant messenger in the social & communications category. There are more than 50 alternatives to Coccinella for a variety of platforms, including Windows, Mac, Linux, Android and iPhone apps. The best Coccinella alternative is Signal, which is both free and Open Source. Other great apps like Coccinella are Pidgin, Wire, Molly and OpenBoard Whiteboard.
Conceptboard goes beyond the idea of online whiteboards and adds realtime collaboration, document sharing, visual feedback, task management, live meetings and more.
Germany
EU
KakaoTalk is a phone number based messenger service that allows users anywhere in the world to chat one-to-one or in a group for free. (no SMS service)
South Korea
Mark up websites, graphics, and photos, or start brainstorming on a blank canvas. Browse the web with your friends or make that conference call more productive than ever. No plug-ins, downloads, or firewall voodoo - its all here, ready to go when you are.
United States
qutIM - free open-source multiprotocol ( ICQ, Jabber/GTalk/Ya.Online/LiveJournal.com, Mail.Ru, IRC )
Russia
Messenger for Desktop is a wrapper for the official client messenger.com. Therefore it works like a regular browser which can only navigate to the messenger.com web app. MFD doesn't touch your messages, account or personal data. All that is handled securely by Facebook.
RomaniaEU
QQ is a widely used Chinese instant messaging service developed by Tencent, offering chat, voice, and video communication. It integrates social networking features like groups, forums, and customizable avatars to enhance user interaction.
China
Tkabber is a Free and Open Source client for the Jabber instant messaging system. Its writen in Tcl/Tk, and works on many platforms (tested on Linux, FreeBSD, NetBSD, Solaris, MacOS X and Windows 98/2000/XP).
Russia
Pinger lets you text and talk free with the people you care about most, anywhere on the planet. Tap a picture and you'll see all of your communications—texts, pics, calls, voicemails—all in one place.
United States
Groupboard is a free collaborative whiteboard (drawing board), allowing you to draw and chat in real time with other people anywhere on the internet, even with users using a web browser or an iPhone/iPad. Use it for online tutoring, collaborative design, or just for fun!
United States
Messenger Kids is a free video calling and messaging app designed for kids to connect with close friends and family from their tablet or smartphone. Kids can only connect with parent-approved contacts, which creates a more controlled environment.
United States
MCabber is a small XMPP (Jabber) console client. It includes features such as SASL/SSL/TLS support, MUC (Multi-User Chat) support, history logging, command completion, OpenPGP encryption, OTR (Off-the-Record Messaging) support, dynamic modules and external action triggers.
FranceEU
Ayttm is an instant messaging (aka chat) client that provides all-in-one chat functionality for several major instant messaging services from one simple program. Ayttm "Contacts" allow you to refer to several accounts of the same person from a single contact name...
