Add a C extension that doesn't yet do anything.

.gitignore

@@ -5,3 +5,5 @@ pkg
 *.rbc
 .rvmrc
 .ruby-version
+*.bundle
+/tmp

Rakefile

@@ -1,5 +1,6 @@
 require 'rake'
 require 'rake/testtask'
+require 'rake/extensiontask'
 $LOAD_PATH.unshift File.expand_path("../lib", __FILE__)
 require "liquid/version"
 
@@ -75,3 +76,7 @@ desc "Run example"
 task :example do
   ruby "-w -d -Ilib example/server/server.rb"
 end
+
+Rake::ExtensionTask.new "liquid" do |ext|
+  ext.lib_dir = "lib/liquid"
+end

ext/liquid/extconf.rb

@@ -0,0 +1,2 @@
+require 'mkmf'
+create_makefile("liquid/liquid")

ext/liquid/liquid_ext.c

@@ -0,0 +1,6 @@
+#include "ruby.h"
+
+void Init_liquid(void)
+{
+    VALUE mLiquid = rb_define_module("Liquid");
+}

liquid.gemspec

@@ -19,8 +19,11 @@ Gem::Specification.new do |s|
 
   s.test_files  = Dir.glob("{test}/**/*")
   s.files       = Dir.glob("{lib}/**/*") + %w(MIT-LICENSE README.md)
+  s.extensions  = ['ext/liquid/extconf.rb']
 
   s.extra_rdoc_files  = ["History.md", "README.md"]
 
   s.require_path = "lib"
+
+  s.add_development_dependency 'rake-compiler'
 end