diff --git a/crew b/crew
index 57190bc35..6b7f42d90 100755
--- a/crew
+++ b/crew
@@ -5,8 +5,11 @@ require 'uri'
 require 'digest/sha2'
 require 'json'
 require 'fileutils'
+require_relative 'lib/color'
+require_relative 'lib/const'
 
-# Constants definitions
+# Add lib to LOAD_PATH
+$LOAD_PATH.unshift "#{CREW_LIB_PATH}lib"
 
 DOC = <<DOCOPT
 Chromebrew - Package manager for Chrome OS http://skycocker.github.io/chromebrew/
@@ -30,49 +33,11 @@ Usage:
 version 0.4.3
 DOCOPT
 
-ARCH = `uname -m`.strip
-ARCH_LIB = if ARCH == 'x86_64' then 'lib64' else 'lib' end
-
-CREW_PREFIX = '/usr/local'
-CREW_LIB_PREFIX = CREW_PREFIX + '/' + ARCH_LIB
-
-CREW_LIB_PATH = CREW_PREFIX + '/lib/crew/'
-CREW_CONFIG_PATH = CREW_PREFIX + '/etc/crew/'
-CREW_BREW_DIR = CREW_PREFIX + '/tmp/crew/'
-CREW_DEST_DIR = CREW_BREW_DIR + 'dest'
-CREW_DEST_PREFIX = CREW_DEST_DIR + CREW_PREFIX
-CREW_DEST_LIB_PREFIX = CREW_DEST_DIR + CREW_LIB_PREFIX
-
-# Set CREW_NPROC from environment variable or `nproc`
-if ENV["CREW_NPROC"].to_s == ''
-  CREW_NPROC = `nproc`.strip
-else
-  CREW_NPROC = ENV["CREW_NPROC"]
-end
-
-# Set CREW_NOT_COMPRESS from environment variable
-CREW_NOT_COMPRESS = ENV["CREW_NOT_COMPRESS"]
-
-# Set CREW_NOT_STRIP from environment variable
-CREW_NOT_STRIP = ENV["CREW_NOT_STRIP"]
-
-# Set XZ_OPT environment variable for build command.
-# If CREW_XZ_OPT is defined, use it by default.  Use `-7e`, otherwise.
-if ENV["CREW_XZ_OPT"].to_s == ''
-  ENV["XZ_OPT"] = "-7e"
-else
-  ENV["XZ_OPT"] = ENV["CREW_XZ_OPT"]
-end
-
-USER = `whoami`.chomp
-
-# Add lib to LOAD_PATH
-
-$LOAD_PATH.unshift "#{CREW_LIB_PATH}lib"
+# Disallow sudo
+abort "Chromebrew should not be run as root.".lightred if Process.uid == 0
 
 # Parse arguments using docopt
-
-require 'docopt'
+require_relative 'lib/docopt'
 begin
   args = Docopt::docopt(DOC)
 rescue Docopt::Exit => e
@@ -84,80 +49,6 @@ end
 @opt_verbose = args["--verbose"]
 @opt_src = args["--build-from-source"]
 
-# colorization
-class String
-  def colorize(color_code, shade)
-    "\e[#{shade};#{color_code}m#{self}\e[0m"
-  end
-
-  def black
-    colorize(30, 0)
-  end
-
-  def red
-    colorize(31, 0)
-  end
-
-  def green
-    colorize(32, 0)
-  end
-
-  def orange
-    colorize(33, 0)
-  end
-
-  def blue
-    colorize(34, 0)
-  end
-
-  def purple
-    colorize(35, 0)
-  end
-
-  def cyan
-    colorize(36, 0)
-  end
-
-  def lightgray
-    colorize(37, 0)
-  end
-
-  def gray
-    colorize(30, 1)
-  end
-
-  def lightred
-    colorize(31, 1)
-  end
-
-  def lightgreen
-    colorize(32, 1)
-  end
-
-  def yellow
-    colorize(33, 1)
-  end
-
-  def lightblue
-    colorize(34, 1)
-  end
-
-  def lightpurple
-    colorize(35, 1)
-  end
-
-  def lightcyan
-    colorize(36, 1)
-  end
-
-  def white
-    colorize(37, 1)
-  end
-end
-
-#disallow sudo
-abort "Chromebrew should not be run as root.".lightred if Process.uid == 0
-
 @device = JSON.parse(File.read(CREW_CONFIG_PATH + 'device.json'), symbolize_names: true)
 #symbolize also values
 @device.each do |key, elem|
@@ -203,9 +94,9 @@ end
 
 def regexp_search(pkgName)
   results = Dir["#{CREW_LIB_PATH}packages/*.rb"].sort \
-	  .select  { |f| File.basename(f, '.rb') =~ Regexp.new(pkgName, true) } \
-	  .collect { |f| File.basename(f, '.rb') } \
-	  .each    { |f| print_package(f, @opt_verbose) }
+    .select  { |f| File.basename(f, '.rb') =~ Regexp.new(pkgName, true) } \
+    .collect { |f| File.basename(f, '.rb') } \
+    .each    { |f| print_package(f, @opt_verbose) }
   if results.empty?
     Find.find ("#{CREW_LIB_PATH}packages/") do |packageName|
       if File.file? packageName
@@ -654,7 +545,7 @@ def install
     # perform post-install process
     post_install dest_dir
   end
-	
+
   #add to installed packages
   @device[:installed_packages].push(name: @pkg.name, version: @pkg.version)
   File.open(CREW_CONFIG_PATH + 'device.json', 'w') do |file|
diff --git a/lib/color.rb b/lib/color.rb
new file mode 100644
index 000000000..d05c56bfc
--- /dev/null
+++ b/lib/color.rb
@@ -0,0 +1,70 @@
+# Colorization for strings
+class String
+  def colorize(color_code, shade)
+    "\e[#{shade};#{color_code}m#{self}\e[0m"
+  end
+
+  def black
+    colorize(30, 0)
+  end
+
+  def red
+    colorize(31, 0)
+  end
+
+  def green
+    colorize(32, 0)
+  end
+
+  def orange
+    colorize(33, 0)
+  end
+
+  def blue
+    colorize(34, 0)
+  end
+
+  def purple
+    colorize(35, 0)
+  end
+
+  def cyan
+    colorize(36, 0)
+  end
+
+  def lightgray
+    colorize(37, 0)
+  end
+
+  def gray
+    colorize(30, 1)
+  end
+
+  def lightred
+    colorize(31, 1)
+  end
+
+  def lightgreen
+    colorize(32, 1)
+  end
+
+  def yellow
+    colorize(33, 1)
+  end
+
+  def lightblue
+    colorize(34, 1)
+  end
+
+  def lightpurple
+    colorize(35, 1)
+  end
+
+  def lightcyan
+    colorize(36, 1)
+  end
+
+  def white
+    colorize(37, 1)
+  end
+end
diff --git a/lib/const.rb b/lib/const.rb
new file mode 100644
index 000000000..cb7971f6d
--- /dev/null
+++ b/lib/const.rb
@@ -0,0 +1,37 @@
+# Defines common constants used in different parts of crew
+
+ARCH = `uname -m`.strip
+ARCH_LIB = if ARCH == 'x86_64' then 'lib64' else 'lib' end
+
+CREW_PREFIX = '/usr/local'
+CREW_LIB_PREFIX = CREW_PREFIX + '/' + ARCH_LIB
+
+CREW_LIB_PATH = CREW_PREFIX + '/lib/crew/'
+CREW_CONFIG_PATH = CREW_PREFIX + '/etc/crew/'
+CREW_BREW_DIR = CREW_PREFIX + '/tmp/crew/'
+CREW_DEST_DIR = CREW_BREW_DIR + 'dest'
+CREW_DEST_PREFIX = CREW_DEST_DIR + CREW_PREFIX
+CREW_DEST_LIB_PREFIX = CREW_DEST_DIR + CREW_LIB_PREFIX
+
+# Set CREW_NPROC from environment variable or `nproc`
+if ENV["CREW_NPROC"].to_s == ''
+  CREW_NPROC = `nproc`.strip
+else
+  CREW_NPROC = ENV["CREW_NPROC"]
+end
+
+# Set CREW_NOT_COMPRESS from environment variable
+CREW_NOT_COMPRESS = ENV["CREW_NOT_COMPRESS"]
+
+# Set CREW_NOT_STRIP from environment variable
+CREW_NOT_STRIP = ENV["CREW_NOT_STRIP"]
+
+# Set XZ_OPT environment variable for build command.
+# If CREW_XZ_OPT is defined, use it by default.  Use `-7e`, otherwise.
+if ENV["CREW_XZ_OPT"].to_s == ''
+  ENV["XZ_OPT"] = "-7e"
+else
+  ENV["XZ_OPT"] = ENV["CREW_XZ_OPT"]
+end
+
+USER = `whoami`.chomp