diff --git a/Library/Homebrew/dependencies.rb b/Library/Homebrew/dependencies.rb
index 7c2ff7d1b0..16d2768f25 100644
--- a/Library/Homebrew/dependencies.rb
+++ b/Library/Homebrew/dependencies.rb
@@ -143,212 +143,4 @@ class Requirement
   end
 end
 
-
-# A dependency on a language-specific module.
-class LanguageModuleDependency < Requirement
-  def initialize language, module_name, import_name=nil
-    @language = language
-    @module_name = module_name
-    @import_name = import_name || module_name
-  end
-
-  def fatal?; true; end
-
-  def satisfied?
-    quiet_system(*the_test)
-  end
-
-  def message; <<-EOS.undent
-    Unsatisfied dependency: #{@module_name}
-    Homebrew does not provide #{@language.to_s.capitalize} dependencies; install with:
-      #{command_line} #{@module_name}
-    EOS
-  end
-
-  def the_test
-    case @language
-      when :chicken then %W{/usr/bin/env csi -e (use #{@import_name})}
-      when :jruby then %W{/usr/bin/env jruby -rubygems -e require\ '#{@import_name}'}
-      when :lua then %W{/usr/bin/env luarocks show #{@import_name}}
-      when :node then %W{/usr/bin/env node -e require('#{@import_name}');}
-      when :perl then %W{/usr/bin/env perl -e use\ #{@import_name}}
-      when :python then %W{/usr/bin/env python -c import\ #{@import_name}}
-      when :ruby then %W{/usr/bin/env ruby -rubygems -e require\ '#{@import_name}'}
-      when :rbx then %W{/usr/bin/env rbx -rubygems -e require\ '#{@import_name}'}
-    end
-  end
-
-  def command_line
-    case @language
-      when :chicken then "chicken-install"
-      when :jruby   then "jruby -S gem install"
-      when :lua     then "luarocks install"
-      when :node    then "npm install"
-      when :perl    then "cpan -i"
-      when :python  then "pip install"
-      when :rbx     then "rbx gem install"
-      when :ruby    then "gem install"
-    end
-  end
-end
-
-
-# This requirement is used to require an X11 implementation,
-# optionally with a minimum version number.
-class X11Dependency < Requirement
-  include Comparable
-  attr_reader :min_version
-
-  def initialize min_version=nil
-    @min_version = min_version
-  end
-
-  def fatal?; true; end
-
-  def satisfied?
-    MacOS::XQuartz.installed? and (@min_version.nil? or @min_version <= MacOS::XQuartz.version)
-  end
-
-  def message; <<-EOS.undent
-    Unsatisfied dependency: XQuartz #{@min_version}
-    Homebrew does not package XQuartz. Installers may be found at:
-      https://xquartz.macosforge.org
-    EOS
-  end
-
-  def modify_build_environment
-    ENV.x11
-  end
-
-  def <=> other
-    unless other.is_a? X11Dependency
-      raise TypeError, "expected X11Dependency"
-    end
-
-    if other.min_version.nil?
-      1
-    elsif @min_version.nil?
-      -1
-    else
-      @min_version <=> other.min_version
-    end
-  end
-
-end
-
-
-# There are multiple implementations of MPI-2 available.
-# http://www.mpi-forum.org/
-# This requirement is used to find an appropriate one.
-class MPIDependency < Requirement
-
-  attr_reader :lang_list
-
-  def initialize *lang_list
-    @lang_list = lang_list
-    @non_functional = []
-    @unknown_langs = []
-  end
-
-  def fatal?; true; end
-
-  def mpi_wrapper_works? compiler
-    compiler = which compiler
-    return false if compiler.nil? or not compiler.executable?
-
-    # Some wrappers are non-functional and will return a non-zero exit code
-    # when invoked for version info.
-    #
-    # NOTE: A better test may be to do a small test compilation a la autotools.
-    quiet_system compiler, '--version'
-  end
-
-  def satisfied?
-    @lang_list.each do |lang|
-      case lang
-      when :cc, :cxx, :f90, :f77
-        compiler = 'mpi' + lang.to_s
-        @non_functional << compiler unless mpi_wrapper_works? compiler
-      else
-        @unknown_langs << lang.to_s
-      end
-    end
-
-    @unknown_langs.empty? and @non_functional.empty?
-  end
-
-  def modify_build_environment
-    # Set environment variables to help configure scripts find MPI compilers.
-    # Variable names taken from:
-    # http://www.gnu.org/software/autoconf-archive/ax_mpi.html
-    lang_list.each do |lang|
-      compiler = 'mpi' + lang.to_s
-      mpi_path = which compiler
-
-      # Fortran 90 environment var has a different name
-      compiler = 'MPIFC' if lang == :f90
-      ENV[compiler.upcase] = mpi_path
-    end
-  end
-
-  def message
-    if not @unknown_langs.empty?
-      <<-EOS.undent
-        There is no MPI compiler wrapper for:
-            #{@unknown_langs.join ', '}
-
-        The following values are valid arguments to `MPIDependency.new`:
-            :cc, :cxx, :f90, :f77
-        EOS
-    else
-      <<-EOS.undent
-        Homebrew could not locate working copies of the following MPI compiler
-        wrappers:
-            #{@non_functional.join ', '}
-
-        If you have a MPI installation, please ensure the bin folder is on your
-        PATH and that all the wrappers are functional. Otherwise, a MPI
-        installation can be obtained from homebrew by *picking one* of the
-        following formulae:
-            open-mpi, mpich2
-        EOS
-    end
-  end
-
-end
-
-# This requirement added by the `conflicts_with` DSL method.
-class ConflictRequirement < Requirement
-  attr_reader :formula
-
-  def initialize formula, message
-    @formula = formula
-    @message = message
-  end
-
-  def message; @message; end
-
-  def satisfied?
-    keg = Formula.factory(@formula).prefix
-    not keg.exist? && Keg.new(keg).linked?
-  end
-
-  # The user can chose to force installation even in the face of conflicts.
-  def fatal?
-    not ARGV.force?
-  end
-end
-
-class XCodeDependency < Requirement
-  def fatal?; true; end
-
-  def satisfied?
-    MacOS::Xcode.installed?
-  end
-
-  def message; <<-EOS.undent
-    A full installation of XCode.app is required to compile this software.
-    Installing just the Command Line Tools is not sufficent.
-    EOS
-  end
-end
+require 'requirements'
diff --git a/Library/Homebrew/requirements.rb b/Library/Homebrew/requirements.rb
new file mode 100644
index 0000000000..b7cc68a7c8
--- /dev/null
+++ b/Library/Homebrew/requirements.rb
@@ -0,0 +1,208 @@
+# A dependency on a language-specific module.
+class LanguageModuleDependency < Requirement
+  def initialize language, module_name, import_name=nil
+    @language = language
+    @module_name = module_name
+    @import_name = import_name || module_name
+  end
+
+  def fatal?; true; end
+
+  def satisfied?
+    quiet_system(*the_test)
+  end
+
+  def message; <<-EOS.undent
+    Unsatisfied dependency: #{@module_name}
+    Homebrew does not provide #{@language.to_s.capitalize} dependencies; install with:
+      #{command_line} #{@module_name}
+    EOS
+  end
+
+  def the_test
+    case @language
+      when :chicken then %W{/usr/bin/env csi -e (use #{@import_name})}
+      when :jruby then %W{/usr/bin/env jruby -rubygems -e require\ '#{@import_name}'}
+      when :lua then %W{/usr/bin/env luarocks show #{@import_name}}
+      when :node then %W{/usr/bin/env node -e require('#{@import_name}');}
+      when :perl then %W{/usr/bin/env perl -e use\ #{@import_name}}
+      when :python then %W{/usr/bin/env python -c import\ #{@import_name}}
+      when :ruby then %W{/usr/bin/env ruby -rubygems -e require\ '#{@import_name}'}
+      when :rbx then %W{/usr/bin/env rbx -rubygems -e require\ '#{@import_name}'}
+    end
+  end
+
+  def command_line
+    case @language
+      when :chicken then "chicken-install"
+      when :jruby   then "jruby -S gem install"
+      when :lua     then "luarocks install"
+      when :node    then "npm install"
+      when :perl    then "cpan -i"
+      when :python  then "pip install"
+      when :rbx     then "rbx gem install"
+      when :ruby    then "gem install"
+    end
+  end
+end
+
+
+# This requirement is used to require an X11 implementation,
+# optionally with a minimum version number.
+class X11Dependency < Requirement
+  include Comparable
+  attr_reader :min_version
+
+  def initialize min_version=nil
+    @min_version = min_version
+  end
+
+  def fatal?; true; end
+
+  def satisfied?
+    MacOS::XQuartz.installed? and (@min_version.nil? or @min_version <= MacOS::XQuartz.version)
+  end
+
+  def message; <<-EOS.undent
+    Unsatisfied dependency: XQuartz #{@min_version}
+    Homebrew does not package XQuartz. Installers may be found at:
+      https://xquartz.macosforge.org
+    EOS
+  end
+
+  def modify_build_environment
+    ENV.x11
+  end
+
+  def <=> other
+    unless other.is_a? X11Dependency
+      raise TypeError, "expected X11Dependency"
+    end
+
+    if other.min_version.nil?
+      1
+    elsif @min_version.nil?
+      -1
+    else
+      @min_version <=> other.min_version
+    end
+  end
+
+end
+
+
+# There are multiple implementations of MPI-2 available.
+# http://www.mpi-forum.org/
+# This requirement is used to find an appropriate one.
+class MPIDependency < Requirement
+
+  attr_reader :lang_list
+
+  def initialize *lang_list
+    @lang_list = lang_list
+    @non_functional = []
+    @unknown_langs = []
+  end
+
+  def fatal?; true; end
+
+  def mpi_wrapper_works? compiler
+    compiler = which compiler
+    return false if compiler.nil? or not compiler.executable?
+
+    # Some wrappers are non-functional and will return a non-zero exit code
+    # when invoked for version info.
+    #
+    # NOTE: A better test may be to do a small test compilation a la autotools.
+    quiet_system compiler, '--version'
+  end
+
+  def satisfied?
+    @lang_list.each do |lang|
+      case lang
+      when :cc, :cxx, :f90, :f77
+        compiler = 'mpi' + lang.to_s
+        @non_functional << compiler unless mpi_wrapper_works? compiler
+      else
+        @unknown_langs << lang.to_s
+      end
+    end
+
+    @unknown_langs.empty? and @non_functional.empty?
+  end
+
+  def modify_build_environment
+    # Set environment variables to help configure scripts find MPI compilers.
+    # Variable names taken from:
+    # http://www.gnu.org/software/autoconf-archive/ax_mpi.html
+    lang_list.each do |lang|
+      compiler = 'mpi' + lang.to_s
+      mpi_path = which compiler
+
+      # Fortran 90 environment var has a different name
+      compiler = 'MPIFC' if lang == :f90
+      ENV[compiler.upcase] = mpi_path
+    end
+  end
+
+  def message
+    if not @unknown_langs.empty?
+      <<-EOS.undent
+        There is no MPI compiler wrapper for:
+            #{@unknown_langs.join ', '}
+
+        The following values are valid arguments to `MPIDependency.new`:
+            :cc, :cxx, :f90, :f77
+        EOS
+    else
+      <<-EOS.undent
+        Homebrew could not locate working copies of the following MPI compiler
+        wrappers:
+            #{@non_functional.join ', '}
+
+        If you have a MPI installation, please ensure the bin folder is on your
+        PATH and that all the wrappers are functional. Otherwise, a MPI
+        installation can be obtained from homebrew by *picking one* of the
+        following formulae:
+            open-mpi, mpich2
+        EOS
+    end
+  end
+
+end
+
+# This requirement added by the `conflicts_with` DSL method.
+class ConflictRequirement < Requirement
+  attr_reader :formula
+
+  def initialize formula, message
+    @formula = formula
+    @message = message
+  end
+
+  def message; @message; end
+
+  def satisfied?
+    keg = Formula.factory(@formula).prefix
+    not keg.exist? && Keg.new(keg).linked?
+  end
+
+  # The user can chose to force installation even in the face of conflicts.
+  def fatal?
+    not ARGV.force?
+  end
+end
+
+class XCodeDependency < Requirement
+  def fatal?; true; end
+
+  def satisfied?
+    MacOS::Xcode.installed?
+  end
+
+  def message; <<-EOS.undent
+    A full installation of XCode.app is required to compile this software.
+    Installing just the Command Line Tools is not sufficent.
+    EOS
+  end
+end