You should start by downloading
the *.tar.bz2 version of Rainlendar and uncompressing the files to some folder. Then just try to run rainlendar2
from the folder. If that doesn't work you can try to run the application from the terminal with "--debug" command line argument to enable the debugging. You can then check from the debug log
for possible errors.
If Rainlendar doesn't start it usually means that you don't have some 3rd party library installed or you have too old version of it. In most non-Ubuntu systems especially the required openssl library version is quite often older than what Rainlendar expects.