This page is for source code download, and you are supposedly using Ubuntu (newer than 12.04) or CentOS (newer 7)as your host OS.
Please execute the following command to update.
For Ubuntu system:

$ sudo apt-get update; sudo apt-get upgrade -y; sudo apt-get install -y wget git

For CentOS system:

$ sudo yum update -y; sudo yum install -y wget git

Download

you can just do following step if you are updating the latest version.

$ git clone https://github.com/open-estuary/estuary.git

If need, you can download the whole source code just do following command.

$ repo init -u "https://github.com/open-estuary/estuary.git" -b refs/tags/(version tag) --no-repo-verify --repo-url=git://android.git.linaro.org/tools/repo
$ false;while [ $? -ne 0 ];do repo sync;done

Manual Download

Estuary             : git clone https://github.com/open-estuary/estuary.git
Distro-repo         : git clone https://github.com/open-estuary/distro-repo.git
UEFI for D05        : git clone https://github.com/open-estuary/estuary-uefi.git
UEFI for D03        : git clone https://github.com/open-estuary/estuary-uefi.git
Linux Kernel        : git clone https://github.com/open-estuary/kernel.git 

More detail information about system setup, please refer to Estuary User Manual.
Overview introduction to this project, please refer to Estuary Overview.