Qucs-S is a spin-off of Qucs. It allows to use several SPICE and non-SPICE simulation kernels. See https://ra3xdh.github.io/ for more details. It is based on original Qucs code: https://github.com/Qucs/qucs
Use CMake to build Qucs-S. Install all necessary dependecies: GCC, Qt, and SPICE (optional). Clone this git repository and execute in the top directory:
mkdir builddir
cd builddir
cmake .. -DCMAKE_INSTALL_PREFIX=/your_install_prefix/
make
make install
Where /your_install_prefix/ is desired installation directory. Substitute any
desire path (for example $HOME/qucs-s) here. You may omit this option and
installation steps. Default installation directory will be /usr/local if
CMAKE_INSTALL_PREFIX is not defined.
Then run qucs-s executable to launch application:
cd /your_installation prefix/bin
./qucs-s