Pidgin

Pidgin is a multi-protocol IM client for GNU/Linux desktops. It is woefully crap in many technical ways, but mostly does what it says on the tin. Except:

Patch it to support XMPP XEP-0280 Message Carbons

This is the bit that lets XMPP clients track message history like Hangouts does, when you are using multiple clients in a conversation (e.g. phone, tablet, gaming PC, work laptop). The perfectly working patch by "xnyhps" has been lurking on Ticket #15508 since January 2014 and nobody seems to be paying attention, because they think it's more important to support useless non-features like Realtime text and message receipts in the next release. Luckily, these instructions will build you a modified version you can install yourself:

apt-get source pidgin
sudo apt-get build-dep pidgin
cd pidgin-2.10.9
wget https://developer.pidgin.im/raw-attachment/ticket/15508/carbons.5.patch
patch -p1 < carbons.5.patch
dpkg-source --commit
vi debian/changelog  # bump to +nmu1
dpkg-buildpackage  # -us -uc if you can't be arsed with a PGP key
sudo dpkg -i ../pidgin*.deb ../libpurple*.deb

See also

• Use Prosody to run your own XMPP (jabber) server, it's easy.
• Use Conversations on your Android gadget.