diff --git a/pisi/__init__.py b/pisi/__init__.py
index c165ea8e..cc3a101e 100644
--- a/pisi/__init__.py
+++ b/pisi/__init__.py
@@ -12,9 +12,9 @@
 
 # PiSi version
 
-__version__ = "1.0.3"
+__version__ = "1.0.4"
 
-__dbversion__ = "1.0.2"
+__dbversion__ = "1.0.4"
 
 __all__ = [ 'api', 'config', 'packagedb', 'installdb', 'search' ]
 
diff --git a/pisi/api.py b/pisi/api.py
index 117a3971..37470edf 100644
--- a/pisi/api.py
+++ b/pisi/api.py
@@ -37,9 +37,9 @@ import pisi.sourcedb
 import pisi.component as component
 from pisi.index import Index
 import pisi.cli
-from pisi.operations import install, remove, upgrade
-from pisi.build import build, build_until
-from pisi.atomicoperations import resurrect_package
+from pisi.operations import install, remove, upgrade, emerge
+from pisi.build import build_until
+from pisi.atomicoperations import resurrect_package, build
 from pisi.metadata import MetaData
 from pisi.files import Files
 import pisi.search
@@ -73,13 +73,14 @@ def init(database = True, options = None, ui = None, comar = True):
         ctx.filesdb = pisi.files.FilesDB()
         ctx.componentdb = pisi.component.ComponentDB()
         packagedb.init_db()
-        pisi.sourcedb.init()
+        ctx.sourcedb = pisi.sourcedb.init()
         pisi.search.init(['summary', 'description'], ['en', 'tr'])
     else:
         ctx.repodb = None
         ctx.installdb = None
         ctx.filesdb = None
         ctx.componentdb = None
+        ctx.sourcedb = None
     ctx.ui.debug('PISI API initialized')
     ctx.initialized = True
 
diff --git a/pisi/atomicoperations.py b/pisi/atomicoperations.py
index 2ec61ad7..def644bd 100644
--- a/pisi/atomicoperations.py
+++ b/pisi/atomicoperations.py
@@ -429,6 +429,14 @@ class Remove(AtomicOperation):
 def remove_single(package_name):
     Remove(package_name).run()
 
+def build(package, authinfo=None):
+    # wrapper for build op`
+    if package.endswith('.xml'):
+        import pisi.build
+        pisi.build.build(package, authinfo)
+    #else:
+    #    ...
+
 def __is_virtual_upgrade(metadata):
 
     pkg = metadata.package
diff --git a/pisi/build.py b/pisi/build.py
index bae179cb..ca840f16 100644
--- a/pisi/build.py
+++ b/pisi/build.py
@@ -43,7 +43,7 @@ import pisi.component as component
 class Error(pisi.Error):
     pass
 
-
+    
 # Helper Functions
 def get_file_type(path, pinfo_list, install_dir):
     """Return the file type of a path according to the given PathInfo
diff --git a/pisi/cli/commands.py b/pisi/cli/commands.py
index 2fc1010b..5978350f 100644
--- a/pisi/cli/commands.py
+++ b/pisi/cli/commands.py
@@ -320,10 +320,14 @@ def ignoredep_opt(self):
 class Build(Command):
     """Build a PISI package using a pspec.xml file
 
-Usage: build <pspec.xml>
+Usage: build [<pspec.xml> | <sourcename>] ...
 
 You can give a URI of the pspec.xml file. PISI will
 fetch all necessary files and build the package for you.
+
+Alternatively, you can give the name of a source package
+to be downloaded from a repository containing sources.
+
 """
     __metaclass__ = autocommand
 
@@ -350,8 +354,8 @@ fetch all necessary files and build the package for you.
 
         self.init(database = True)
         ctx.ui.info(_('Output directory: %s') % ctx.config.options.output_dir)
-        for arg in self.args:
-            pisi.api.build(arg, self.authInfo)
+        for x in self.args:
+            pisi.api.build(x, self.authInfo)
         self.finalize()
 
 
@@ -935,6 +939,42 @@ Gives a brief list of PiSi components published in the repositories.
         self.finalize()
 
 
+class ListSources(Command):
+    """List available sources
+
+Usage: list-sources
+
+Gives a brief list of sources published in the repositories.
+"""
+    __metaclass__ = autocommand
+
+    def __init__(self):
+        super(ListSources, self).__init__()
+
+    name = ("list-sources", "ls")
+
+    def options(self):
+        self.parser.add_option("-l", "--long", action="store_true",
+                               default=False, help=_("show in long format"))
+
+    def run(self):
+
+        self.init(True)
+
+        list = ctx.sourcedb.list()
+        list.sort()
+        for p in list:
+            source = ctx.sourcedb.get_source(p)
+            if self.options.long:
+                ctx.ui.info(unicode(component))
+            else:
+                lenp = len(p)
+                #if p in installed_list:
+                #    p = colorize(p, 'cyan')
+                p = p + ' ' * max(0, 15 - lenp)
+                ctx.ui.info('%s - %s ' % (source.name, unicode(source.summary)))
+        self.finalize()
+
 class ListUpgrades(Command):
     """List packages to be upgraded
 
diff --git a/pisi/index.py b/pisi/index.py
index 3b0edc02..be56d9cf 100644
--- a/pisi/index.py
+++ b/pisi/index.py
@@ -26,6 +26,7 @@ import pisi.context as ctx
 import pisi.specfile as specfile
 import pisi.metadata as metadata
 import pisi.packagedb as packagedb
+import pisi.sourcedb as sourcedb
 import pisi.util as util
 from pisi.package import Package
 from pisi.pxml.xmlfile import XmlFile
@@ -85,6 +86,8 @@ class Index(XmlFile):
             ctx.componentdb.update_component(comp)
         for pkg in self.packages:
             pkgdb.add_package(pkg)
+        for src in self.sources:
+            ctx.sourcedb.add_source(src, repo)
 
     def add_package(self, path, repo_uri):
         package = Package(path, 'r')
diff --git a/pisi/operations.py b/pisi/operations.py
index b93ce086..4505b1ab 100644
--- a/pisi/operations.py
+++ b/pisi/operations.py
@@ -41,6 +41,7 @@ class Error(pisi.Error):
     pass
 
 # high level operations
+
 def install(packages, reinstall = False):
     """install a list of packages (either files/urls, or names)"""
 
@@ -495,3 +496,147 @@ def plan_remove(A):
         G_f.write_graphviz(sys.stdout)
     order = G_f.topological_sort()
     return G_f, order
+
+def expand_src_components(A):
+    Ap = set()
+    for x in A:
+        if ctx.componentdb.has_component(x):
+            Ap = Ap.union(ctx.componentdb.get_component(x).sources)
+        else:
+            Ap.add(x)
+    return Ap
+
+##def build_names(A, rebuild = true):
+##
+##    # A was a list, remove duplicates and expand components
+##    A_0 = A = expand_src_components(set(A))
+##    ctx.ui.debug('A = %s' % str(A))
+##
+##    # filter packages that are already installed
+##    if not rebuild:
+##        Ap = set(filter(lambda x: not ctx.installdb.is_installed(x), A))
+##        d = A - Ap
+##        if len(d) > 0:
+##            ctx.ui.warning(_('Not re-building the following packages: ') +
+##                           util.strlist(d))
+##            A = Ap
+##
+##    if len(A)==0:
+##        ctx.ui.info(_('No packages to build.'))
+##        return
+##        
+##    if not ctx.config.get_option('ignore_dependency'):
+##        G_f, order_inst = plan_build_pkg_names(A)
+##    else:
+##        G_f = None
+##        order_inst = []
+##
+##    ctx.ui.info(_("""The following minimal list of packages will be installed
+##in the respective order to satisfy dependencies:
+##""") + util.strlist(order))
+##
+##    if ctx.get_option('dry_run'):
+##        return
+##
+##    if len(order) > len(A_0):
+##        if not ctx.ui.confirm(_('There are extra packages due to dependencies. Do you want to continue?')):
+##            return False
+##            
+##    ctx.ui.notify(ui.packagestogo, order = order)
+##            
+##    for x in order:
+##        atomicoperations.install_single_name(x)
+##
+##def plan_build_names(A):
+##    # try to construct a pisi graph of packages to
+##    # install / reinstall
+##
+##    G_f = pgraph.PGraph(packagedb)               # construct G_f
+##
+##    # find the "install closure" graph of G_f by package 
+##    # set A using packagedb
+##    for x in A:
+##        G_f.add_package(x)
+##    B = A
+##    
+##    while len(B) > 0:
+##        Bp = set()
+##        for x in B:
+##            pkg = packagedb.get_package(x)
+##            for dep in pkg.runtimeDependencies():
+##                ctx.ui.debug('checking %s' % str(dep))
+##                # we don't deal with already *satisfied* dependencies
+##                if not dependency.installed_satisfies_dep(dep):
+##                    if not dep.package in G_f.vertices():
+##                        Bp.add(str(dep.package))
+##                    G_f.add_dep(x, dep)
+##        B = Bp
+##    if ctx.config.get_option('debug'):
+##        G_f.write_graphviz(sys.stdout)
+##    order = G_f.topological_sort()
+##    order.reverse()
+##    check_conflicts(order)
+##    return G_f, order
+
+def emerge(A):
+
+    # A was a list, remove duplicates and expand components
+    A_0 = A = expand_src_components(set(A))
+    ctx.ui.debug('A = %s' % str(A))
+
+    if len(A)==0:
+        ctx.ui.info(_('No packages to build.'))
+        return
+        
+    if not ctx.config.get_option('ignore_dependency'):
+        G_f, order = plan_emerge(A)
+    else:
+        G_f = None
+        order_inst = []
+
+    ctx.ui.info(_("""The following minimal list of packages will be built and
+installed in the respective order to satisfy dependencies:
+""") + util.strlist(order))
+
+    if ctx.get_option('dry_run'):
+        return
+
+    if len(order) > len(A_0):
+        if not ctx.ui.confirm(_('There are extra packages due to dependencies. Do you want to continue?')):
+            return False
+            
+    ctx.ui.notify(ui.packagestogo, order = order)
+            
+    for x in order:
+        atomicoperations.install_single_name(x)
+
+def plan_emerge(A):
+    # try to construct a pisi graph of packages to
+    # install / reinstall
+
+    G_f = pgraph.PGraph(packagedb)               # construct G_f
+
+    # find the "install closure" graph of G_f by package 
+    # set A using packagedb
+    for x in A:
+        G_f.add_package(x)
+    B = A
+    
+    while len(B) > 0:
+        Bp = set()
+        for x in B:
+            pkg = packagedb.get_package(x)
+            for dep in pkg.runtimeDependencies():
+                ctx.ui.debug('checking %s' % str(dep))
+                # we don't deal with already *satisfied* dependencies
+                if not dependency.installed_satisfies_dep(dep):
+                    if not dep.package in G_f.vertices():
+                        Bp.add(str(dep.package))
+                    G_f.add_dep(x, dep)
+        B = Bp
+    if ctx.config.get_option('debug'):
+        G_f.write_graphviz(sys.stdout)
+    order = G_f.topological_sort()
+    order.reverse()
+    check_conflicts(order)
+    return G_f, order
diff --git a/pisi/repodb.py b/pisi/repodb.py
index d477320f..4033a111 100644
--- a/pisi/repodb.py
+++ b/pisi/repodb.py
@@ -51,7 +51,7 @@ class RepoDB(object):
         # initialize package/source dbs
         for x in self.list():
             packagedb.add_db(x)
-
+            
     def close(self):
         self.d.close()
 
diff --git a/pisi/sourcedb.py b/pisi/sourcedb.py
index d9a85e6d..91d2bda0 100644
--- a/pisi/sourcedb.py
+++ b/pisi/sourcedb.py
@@ -16,6 +16,9 @@ package source database
 interface for update/query to local package repository
 we basically store everything in sourceinfo class
 yes, we are cheap
+to handle multiple repositories, for sources, we 
+store a set of repositories in which the source appears.
+the actual guy to take is determined from the repo order.
 """
 
 import os
@@ -28,31 +31,60 @@ _ = __trans.ugettext
 import pisi.util as util
 import pisi.context as ctx
 import pisi.lockeddbshelve as shelve
+import pisi.repodb
 
 class SourceDB(object):
 
-    def __init__(self, id = 'repo'):
-        self.d = shelve.LockedDBShelf('source-%s' % id)
+    def __init__(self):
+        self.d = shelve.LockedDBShelf('source')
 
     def close(self):
         self.d.close()
 
+    def list(self):
+        list = []
+        for (pkg, x) in self.d.items():
+            list.append(pkg) # for some reason we couldn't return self.d.items()!! --exa
+        return list
+
     def has_source(self, name):
         name = str(name)
         return self.d.has_key(name)
 
     def get_source(self, name):
         name = str(name)
-        return self.d[name]
+        s = self.d[name]
+        order = ctx.repodb.list()
+        for repo in order:
+            if s.has_key(repo):
+                return s[repo] 
+        return None
 
-    def add_source(self, source_info):
+    def add_source(self, source_info, repo, txn = None):
         assert not source_info.errors()
         name = str(source_info.name)
-        self.d[name] = source_info
-
-    def remove_source(self, name):
+        repo = str(repo)
+        def proc(txn):
+            if not self.d.has_key(name):
+                s = dict()
+            else:
+                s = self.d[name]
+            s[repo] = source_info
+            self.d[name] = s
+        self.d.txn_proc(proc, txn)
+        
+    def remove_source(self, name, repo):
         name = str(name)
-        del self.d[name]
+        repo = str(repo)
+        def proc(txn):
+        #assert self.has_source(name)
+            s = self.d[name]
+            s.remove(repo)
+            if (len(s)==0):
+                del self.d[name]
+            else:
+                self.d[name] = s
+        self.d.txn_proc(proc, txn)
 
 sourcedb = None