kde-style-qtcurve software package provides QtCurve widget style for KDE 4, 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 kde-style-qtcurve
kde-style-qtcurve is installed in your system.
Make ensure the kde-style-qtcurve package were installed using the commands given below,
$ sudo dpkg-query -l | grep kde-style-qtcurve *
You will get with kde-style-qtcurve package name, version, architecture and description in a table
| Distro | Debian 8 jessie |
| Section | KDE |
| Package | kde-style-qtcurve |
| Version | 1.8.14-3+b2 [amd64, armel, arm |
| Description | QtCurve widget style for KDE 4 |
| Sub Section | KDE |