Snapper is open source and licensed under the GPL version 2.0.
You can browse the source code at http://github.com/openSUSE/snapper.
git clone git://github.com/openSUSE/snapper.git
git clone firstname.lastname@example.org:openSUSE/snapper.git
cd snapper make -f Makefile.repo make
Tarballs are available at ftp://ftp.suse.com/pub/projects/snapper/.
To build snapper, you will need at least: autoconf, automake, boost-devel, dbus-1-devel, docbook-xsl-stylesheets, gettext-tools, gcc-c++, libtool, libxml2-devel, make, pam-devel (for optional PAM module), xsltproc
So far there is no dedicated mailing list for snapper development. The authors can be reached on email@example.com.