You need Linux or Cygwin (Notice: On Cygwin pathes may not exceed 260 characters). Other plattforms may work too. We didn't try.
You need rsync. I know rabak doesn't work before version 2.6.4. Maybe even a newer one is required. The newer the better.
You need Perl, I don't know which version. Probably >= 5.8
You need the Mail::Send, Getopt::Long(>= 2.36), and IPC::Run perl modules. Fetch it from CPAN:
cpan -i Mail::Send (or cpan -i MailTools)
cpan -i IPC::Run
cpan -i Getopt::Long
To use dupemerge, you will need the Digest::SHA1 and DBD::SQLite perl modules. To install it do:
cpan -i Digest::SHA1
cpan -i DBD::SQLite