Phusion Passenger
Phusion Passenger ( informally also known as mod_rails and mod_rack among the Ruby community ) is a free web server and application server with support for Ruby , Python and Node . js . 
<triplet> Phusion Passenger <subj> web server <obj> instance of <subj> application server <obj> instance of <subj> Ruby <obj> supports programming language <subj> Python <obj> supports programming language