You can download the software from the official sourceforge project page
Getting Java
Downloading Sphaerica
To run Sphaerica on you Mac, you need to download the sphaerica.jar file from sourceforge. See the list of files for the latest version.
Running the program
Mac OS X
Once you downloaded the file, right click on it. Select Jar Launcher from the Open With menu.
Windows
To run Sphaerica on Windows you can download sphaerica.jar or the prepared sphaerica.exe executable file.Linux
To run Sphaerica on Linux, please download the sphaerica.jar file from sourceforge. When done, open a terminal and cd to the directory in which you downloaded the file. Execute java -jar sphaerica-*.jar command to run the program.