diff --git a/src/fetcher.py b/src/fetcher.py
index fad3194e..49e520cb 100755
--- a/src/fetcher.py
+++ b/src/fetcher.py
@@ -29,14 +29,14 @@ class Fetcher:
         self.percent = 0
         self.rate = 0
 	self.percentHook = None
-
-    def fetch (self):
-        """Return value: Fetched file's full path.."""
         from string import split
         u = urlparse.urlparse(self.uri)
         self.scheme, self.netloc, self.filepath = u[0], u[1], u[2]
         self.filename = split(self.filepath, "/")[-1:][0]
 
+    def fetch (self):
+        """Return value: Fetched file's full path.."""
+
         if self.filename == "":
             self.err("filename error")
 
diff --git a/src/pisi-build b/src/pisi-build
index 3164fb6f..2c6124e4 100755
--- a/src/pisi-build
+++ b/src/pisi-build
@@ -51,11 +51,12 @@ def main():
     util.information("Fetching source from: %s (be patient)\n" % pb.spec.archiveUri)
     pb.fetchArchive(doProgress)
     util.information("Source archive is stored: %s/%s\n" %(pisiconfig.archives_dir, pb.archiveName))
-#     pb.unpackArchive()
-#     pb.applyPatches()
-#     pb.buildSource()
-#     pb.installTarget()
-#     pb.buildPisiPackage()
+    # pb.unpackArchive()
+    # pb.applyPatches()
+    # pb.buildSource()
+    # pb.installTarget()
+
+    pb.buildPackages()
     
 
 if __name__ == "__main__":
diff --git a/src/pisibuild.py b/src/pisibuild.py
index d89f0e3e..b90c7152 100644
--- a/src/pisibuild.py
+++ b/src/pisibuild.py
@@ -1,20 +1,22 @@
 # -*- coding: utf-8 -*-
 
 # python standard library
+import os
 from os.path import basename
 
 from specfile import SpecFile
 from fetcher import Fetcher
 # from archive import Archive
 # import pisipackage
-# import pisiutils # patch, fileutils?
+import util
 import pisiconfig
 
+
 class PisiBuildError(Exception):
     pass
 
 class PisiBuild:
-    """PisiBuild class, provides the package build and creation rutines"""
+    """PisiBuild class, provides the package build and creation routines"""
     def __init__(self, pspecfile):
 	self.pspecfile = pspecfile
 	spec = SpecFile()
@@ -29,9 +31,31 @@ class PisiBuild:
 	"""fetch an archive and store to pisiconfig.archives_dir
 	using fether.Fetcher"""
 	fetch = Fetcher(self.spec.archiveUri)
+
+        # check if source already cached
+        destpath = fetch.filedest + "/" + fetch.filename
+        if os.access(destpath, os.R_OK):
+            if util.md5_file(destpath)==self.spec.archiveMD5:
+                util.information(fetch.filename + " cached")
+                return
+
 	if percentHook:
 	    fetch.percentHook = percentHook
 	fetch.fetch()
 
     def unpackArchive(self):
 	pass
+
+    def applyPatches(self):
+        pass
+
+    def buildSource(self):
+        pass
+
+    def installTarget(self):
+        pass
+
+    def buildPackages(self):
+        for package in self.spec.packages:
+            util.information("** Building package " % package.name);
+    
diff --git a/src/specfile.py b/src/specfile.py
index 0a7e987b..9517e945 100644
--- a/src/specfile.py
+++ b/src/specfile.py
@@ -50,23 +50,22 @@ class SpecFile(XmlFile):
 	archiveNode = self.getNode("Source/Archive")
         self.archiveUri = getNodeText(archiveNode).strip()
 	self.archiveType = getNodeAttribute(archiveNode, "archType")
-	self.archiveHash = getNodeAttribute(archiveNode, "md5sum")
+	self.archiveMD5 = getNodeAttribute(archiveNode, "md5sum")
         patchElts = self.getChildElts("Source/Patches")
-        patches = [ PatchInfo(p) for p in patchElts ]
-        for x in patches:
+        self.patches = [ PatchInfo(p) for p in patchElts ]
+        for x in self.patches:
             print "patch fn:", x.filename
             print "patch ct:", x.compressionType
         buildDepElts = self.getChildElts("Source/BuildDependencies")
-        buildDeps = [DepInfo(d) for d in buildDepElts]
-        for x in buildDeps:
+        self.buildDeps = [DepInfo(d) for d in buildDepElts]
+        for x in self.buildDeps:
             print "dep nm:", x.package
             print "dep vf:", x.versionFrom
 
         # find all binary packages
         packageElts = self.getAllNodes("Package")
-        packages = [PackageInfo(p) for p in packageElts]
-        print packages
-        for x in packages:
+        self.packages = [PackageInfo(p) for p in packageElts]
+        for x in self.packages:
             print 'package', x.name
             
     def verify(self):
diff --git a/src/util.py b/src/util.py
index b826cb5a..5fd31aaa 100644
--- a/src/util.py
+++ b/src/util.py
@@ -3,7 +3,7 @@
 
 import os
 import sys
-import string
+import md5
 
 def information(message):
     sys.stdout.write(message)
@@ -22,6 +22,13 @@ def check_dir(dir):
         check_dir(parent_dir)
         os.mkdir(dir)
 
+def md5_file(filename):
+    m = md5.new()
+    f = file(filename, 'rb')
+    for l in f:
+        m.update(l)
+    return m.hexdigest()
+
 # run a command non-interactively
 def run_batch(cmd):
     print 'running ', cmd