diff --git a/AVRsack/BuildProject b/AVRsack/BuildProject
index 830361e..3932eaf 100755
--- a/AVRsack/BuildProject
+++ b/AVRsack/BuildProject
@@ -50,7 +50,6 @@ def buildHeaderMap
             end
         end
     end
-    p HEADERMAP
 end
 
 def parseInoFiles
@@ -116,30 +115,50 @@ buildHeaderMap
 parseInoFiles
 
 File.open("#{$BUILD_DIR}/Rakefile", 'w') do |rakeFile|
-    SOURCES = FileList.new(ARGV).select {|f| f =~ /\.(c|cpp|cp|cxx|S)$/}
+    SOURCES = Rake::FileList.new(ARGV).select {|f| f =~ /\.(c|cpp|cp|cxx|S)$/}
     INCLUDES= ($CORES+$LIBRARIES).map {|l| " +\n   \" -I'#{l}'\""}.join('')
     rakeFile.print <<END_RAKE
 CC          = '/usr/local/CrossPack-AVR/bin/avr-g++ -c -g -Os -Wall -fno-exceptions -ffunction-sections -fdata-sections -mmcu=#{BUILD['mcu']} -DF_CPU=#{BUILD['f_cpu']} -MMD -DUSB_VID=null -DUSB_PID=null -DARDUINO=105 -I ../..'#{INCLUDES}
 AR          = '/usr/local/CrossPack-AVR/bin/avr-ar crsv'
 LIBRARIES   = [#{$LIBRARIES.map{|l| "'"+l+"'"}.join(' ')}]
 
-def compile(dest, *src)
+def compile(dest, extrainc, *src)
     directory dest
     archive = dest.ext('.a')
     sources = Rake::FileList.new(src)
     objects = sources.pathmap(dest+"/%n.o")
     objects.each_index do |i|
-        file objects[i] => sources[i] do
-            sh "%s '%s' -o '%s'" % [CC, sources[i], objects[i]]
+        file objects[i] => [sources[i],dest] do
+           sh "%s %s '%s' -o '%s'" % [CC, extrainc ? "-I '"+extrainc+"'" : '', sources[i], objects[i]]
         end
     end
     file archive => objects do
         sh ("%s '%s' " % [AR, archive])+objects.map {|o| "'"+o+"'"}.join(" ")
     end
 end
-
-compile('sketch', #{SOURCES.map{|f| "'../../"+f+"'"}.join(', ')})
-END_RAKE
-
+                                 
+def compile_library(lib)
+    extrainc = nil
+    utility  = lib+"/utility"
+    if File::exists?(utility)
+        extrainc = utility
+    end
+    compile(lib.pathmap('lib/%f'), extrainc, *Rake::FileList[lib+"/*.{c,cpp,cp,cxx,S}", lib+"/utility/*.{c,cpp,cp,cxx,S}"])
+end
+                            
+def compile_core(core,variant)
+    list = Rake::FileList[core+"/*.{c,cpp,cp,cxx,S}"]
+    list.add(variant+"/*.{c,cpp,cp,cxx,S}") if variant
+    compile('core', nil, list)
+end
+
+compile('sketch', nil, #{SOURCES.map{|f| "'../../"+f+"'"}.join(', ')})
+compile_core(#{$CORES.map {|c| "'"+c+"'"}.join(", ")})
+END_RAKE
+
+    $LIBRARIES.each do |lib|
+        rakeFile.puts "compile_library('#{lib}')"
+    end
+                                 
 end