Etherpad does not use PHP or Apache.
Etherpad uses Javascript in NodeJS. You should ask your web host if they support NodeJS and if they have a guide for you to get started deploying NodeJS apps to their hosting.
Here are some services that can provide web/Node hosting for you to test/play with:
Node as an Instance
http://nodester.com/
https://no.de/
http://prgmr.com
http://Slicehost.com
http://Linode.com
http://www.nodesocket.com/
Full hosting
http://CloudFoundry.com
http://DreamHost.com
http://aws.amazon.com/ec2/