gajim software package provides GTK+-based Jabber client, you can install in your Debian 8 (Jessie) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gajim
gajim is installed in your system.
Make ensure the gajim package were installed using the commands given below,
$ sudo dpkg-query -l | grep gajim *
You will get with gajim package name, version, architecture and description in a table
| Distro | Debian 8 jessie |
| Section | Network |
| Package | gajim |
| Version | 0.16-1+deb8u1 |
| Description | GTK+-based Jabber client |
| Sub Section | Net |