On Ubuntu, you may simply search for cain in the Software Center application, and then install it. Of course, you can also get the source distribution from sourceforge and follow the instruction below.
For Linux or Unix, use the platform-independent distribution. You will need appropriate versions of Python, wxPython, matplotlib, numpy, and sympy, as well as a C++ compiler. There are platform-specific instructions for installing this software for the following distributions.
I recommend using the current version of GNU GCC. Note that only Python versions 2.4.x through 2.7.x are currently supported. If you do not have the necessary Python packages installed, Cain will show an error message when you attempt to launch the application.
Download the platform-independent distribution and place it in a convenient
location. Then uncompress the zip file.
unzip Cain-1_10.zip
Build the mass action solvers.
cd Cain
make
Then launch the GUI.
python Cain.py&
There are example files in the examples directory.
You can open a file on startup by specifying the file as a command
line argument. For example:
python Cain.py examples/cain/BirthDeath.xml&
To uninstall Cain, simply delete the Cain directory.