Ubuntu

For Ubuntu and Ubuntu-based distributions, a Launchpad PPA is available to download and receive updates.

# add daily builds PPA
sudo add-apt-repository -u ppa:snwh/ppa
# install icon themes
sudo apt install moka-icon-theme faba-icon-theme faba-mono-icons

Debian

There is no official repository for Debian, but you can download the latest version as a .deb file to install manually.

Fedora & openSUSE

For RPM-based distributions, repositories for Moka and instructions for adding said repositories to both Fedora and openSUSE are available on the openSUSE build system.

Arch Linux

Some lovely folks in the Arch community are maintaining Arch User Repository package(s) that provide both the Paper icons and GTK theme.