How to download and setup boulder
Open terminal and run command
git clone https://github.com/letsencrypt/boulder.git
git clone is used to create a copy or clone of boulder repositories.
You pass git clone a repository URL. it supports a few different network protocols and corresponding URL formats.
Also you may download zip file with boulder https://github.com/letsencrypt/boulder/archive/master.zip
Or simply clone boulder with SSH
[email protected]:letsencrypt/boulder.git