On Debian and derivative systems (Ubuntu, Kubuntu, Linux Mint, etc.), Pure Data and many libraries are provided through the official repositories. To install Pure Data, launch a terminal and run:

sudo apt install puredata

Most libraries are available as well. Usually, their name is prefixed with pd- which makes browsing externals easier:

apt search ^pd-

Installing libraries works the same way as installing Pd:

sudo apt install pd-iemnet pd-aubio pd-wiimote

Gem is packaged as gem (without the pd- prefix):

sudo apt install gem

NOTE: Most packages keep their version for a specific release of the operating system. On Ubuntu LTS or Debian stable, you might find a Pd version that is already a few versions behind the most current version. If you don't need any of the new features, this is fine. If you need a more recent version, read below

Getting the most recent version on Debian

Maintainers of the puredata package take care of making the most recent Pd version available through the backports repository. You can enable it by adding it to your sources:

echo "deb http://deb.debian.org/debian $(. /etc/os-release; echo $VERSION_CODENAME)-backports main" | sudo tee -a /etc/apt/sources.list.d/backports.list

Refresh your sources by running:

sudo apt update

Finally, install puredata from backports:

sudo apt install -t bullseye-backports puredata

Make sure to replace bullseye with the Debian release you're using. bullseye was the stable release by the time of this writing.

Getting the most recent version on Ubuntu

Ubuntu also has a backports repository, though their maintainers don't seem to particularly care about Pure Data. However, Ubuntu has the option self-host packages through a personal package archive (PPA). Luckily, someone created builds and put them on their PPA. The steps necessary to install puredata from there are:

Should I get libraries from Deken or from repos?

Depends. Deken usually is more up-to-date. However, packages from the repo are likely better integrated. Compiled binaries that do not link to any other binaries than Pd most likely work well from either Deken or repo. Compiled libraries from Deken that link to other libraries might work only on the system they were originally created on. Packages from the repo - while more out-of-date - don't suffer any compatibility issues and work out-of-the-box. It is generally recommended to use packages from the repos.