I have developed simple micro service using String boot.
I register my service with consul using spring cloud.
Now my question is how another application is written in different language ie. node or PHP consume my service from consul.
You can use Consul HTTP API to get lot of information from Consul (e.g. about registered services as well). To simplify the usage of it there are lot of clients and sdks listed here (there are also libs for PHP). Also you can use DNS Interface for discovery of registered services.