To quickly install dmd within your user directory, run:
curl -fsS https://dlang.org/install.sh | bash -s dmd
Packages for various distributions are provided:
Besides the DMD reference compiler which uses its own backend, there are two other compilers that can be fetched through the dlang.org download section:
GDC and LDC aren't always at the most recent DMD frontend's versions, but provide better optimization levels as well as support for other platforms like e.g. ARM.
See the wiki for more information