15x4 is community running free popular science lectures in CIS and Europe. More at 15x4.org
After cloning project from git, you need to install composer package manager
To install required dependencies, do composer install
To configure local instance, do cp app/config/parameters.yml.dist app/config/parameters.yml. You may want to edit app/config/parameters.yml afterwards, especially DB connection credentials.
To build project itself, do
bin/console doctrine:database:create
bin/console doctrine:schema:update --force
bin/console 15x4:load-fields
bin/console assets:install --symlink
bin/console assetic:dump --env=prod --no-debug
To run application as a site, you need a webserver. You may use whatever you like, but production uses Apache2.
Simplest option is Symfony built-in server, though it has some known issues:
bin/console server:run --env=prod