Not wanting to start a language war, but targeting the jvm give me a good level of confidence that it will work everywhere due to his good backward compatibility.
it also means you need your own vps or dedicated server to run that... and usually a pretty beefy one at that. that weeds 90% of your potential demographic out. you might as well as do a saas with something like this. if you want easy to deploy it should be easily deployable on a $5 digital ocean vps or heroku.
It use a little bit more of memory than a php application for sure, but it work on a small openshift free "gear" as we are dogfooding there (which is 512mb of ram: https://www.openshift.com/products/pricing) with everything crammed in: jetty + mysql on a single node.
