NeutronDevstack
In order to use Quantum with devstack (http://devstack.org) you'll need to add "quantum" and "q-svc" to ENABLED_SERVICES in your localrc. See this page for more details on localrc settings: http://devstack.org/stack.sh.html.
If you want to enable the openvswitch plugin, you'll have to set Q_PLUGIN to "openvswitch" and also add "q-agt" to ENABLED_SERVICES in order to start the openvswitch quantum agent (also in your localrc).
For example:
ENABLED_SERVICES+=",q-svc,quantum,q-agt" Q_PLUGIN=openvswitch
Then run stack.sh as normal.
To enable melange in devstack add "melange" and "m-svc" to the ENABLED_SERVICES (melange requires quantum to be enabled as well).
For example:
ENABLED_SERVICES+=",q-svc,q-agt,m-svc,quantum,melange"