diff --git a/SystemDataBackendLdap.rb b/SystemDataBackendLdap.rb
index aab1c27..a660087 100644
--- a/SystemDataBackendLdap.rb
+++ b/SystemDataBackendLdap.rb
@@ -75,7 +75,7 @@
     def load!(kind)
       @ldapData[kind] = Hash.new if ! @ldapData[kind]
 
-      @ldapData[kind][:internal] = @ldap.search(
+      @ldapData[kind][:int] = @ldap.search(
         :base   => ldapBase(kind),
         :filter => Net::LDAP::Filter::construct(LDAP_FILTER[kind])
       )
@@ -84,7 +84,7 @@
     def load(kind)
       load!(kind) if ! @ldapData[kind]
 
-      @ldapData[kind][:external] = @ldapData[kind][:internal].map do |data|
+      @ldapData[kind][:ext] = @ldapData[kind][:int].map do |data|
         map = { :dn => :id }
         map.merge!(LDAP_MAP[kind]) if LDAP_MAP[kind]
 
@@ -93,16 +93,16 @@
           ydata.merge!({ map[key] || key => value.size==1?value[0]:value.to_a })
         end
         ydata
-      end if ! @ldapData[kind][:external] && @ldapData[kind][:internal]
+      end if ! @ldapData[kind][:ext] && @ldapData[kind][:int]
 
-      @ldapData[kind][:external].each{|ydata| yield ydata} if @ldapData[kind][:external]
+      @ldapData[kind][:ext].each{|ydata| yield ydata} if @ldapData[kind][:ext]
   end
 
   def update(kind, data)
     map = {}
     map.merge!(LDAP_MAP[kind].invert) if LDAP_MAP[kind]
 
-    odata = @ldapData[kind][:external].find{|edata| edata[:id] == data[:id]}
+    odata = @ldapData[kind][:ext].find{|edata| edata[:id] == data[:id]}
 
     data.each do |key,value| 
       pat_key = map[key] ? map[key] : key
@@ -136,7 +136,7 @@
   def replace(kind, data)
     puts 'INFO: do replace'
     puts '----------------'
-    odata = @ldapData[kind][:external].find{|edata| edata[:id] == data[:id]}
+    odata = @ldapData[kind][:ext].find{|edata| edata[:id] == data[:id]}
     delete(odata)
     puts
     insert(kind, data)
diff --git a/controllers/system_data.rb b/controllers/system_data.rb
new file mode 100644
index 0000000..a53089f
--- /dev/null
+++ b/controllers/system_data.rb
@@ -0,0 +1,91 @@
+require 'User'
+require 'Group'
+require 'Site'
+require 'MailAliasRole'
+require 'MailAliasPerson'
+require 'MailAccount'
+
+class SystemDataBackend
+
+  def initialize(backend)
+    @backend = backend
+    @data    = Hash.new
+  end
+
+  def users
+    load(:User)
+  end
+
+  def groups
+    load(:Group)
+  end
+
+  def sites
+    load(:Site)
+  end
+
+  def mailAliasRoles
+    load(:MailAliasRole)
+  end
+
+  def mailAliasPeople
+    load(:MailAliasPerson)
+  end
+
+  def mailAccounts
+    load(:MailAccount)
+  end
+
+  def userByName(name)
+    users.find{|user| user.name == name}
+  end
+
+  def groupByName(name)
+    groups.find{|group| group.name == name}
+  end
+
+  def siteByName(name)
+    sites.find{|site| site.name == name}
+  end
+
+  def usersInGroup(group)
+    case
+    when group.members.instance_of?(Array):
+      Hash[group.members.map{|uid| [uid, userByName(uid)] if userByName(uid)}]
+    when goup.members.nil?:
+      {}
+    else
+      {group.members => userByName(group.members)} if userByName(group.members)
+    end
+  end
+
+  def mailAliasRolesBySite(site)
+    mailAliasRoles.find_all{|mail| mail.site == site.name}
+  end
+
+  def mailAliasPeopleBySite(site)
+    mailAliasPeople.find_all{|mail| mail.site == site.name}
+  end
+
+  def mailAccountsBySite(site)
+    mailAccounts.find_all{|mail| mail.site == site.name}
+  end
+
+  private
+
+  def load(kind)
+    load!(kind) if ! @data[kind]
+    @data[kind]
+  end
+
+  def load!(kind)
+    @data[kind] = Array.new
+    @backend.load(kind) do |data|
+      data[:backend] = @backend
+      @data[kind].push(
+        eval(kind.to_s + '.new(data)')
+      )
+    end
+  end
+
+end
diff --git a/database.rb b/database.rb
new file mode 100644
index 0000000..1db079c
--- /dev/null
+++ b/database.rb
@@ -0,0 +1,10 @@
+module SdAdmin::Database
+  class Ldap
+    require 'database/base.rb'
+    require 'net/ldap'
+
+    include Enumerable
+  end
+
+  require 'database/ldap'
+end
diff --git a/database/base.rb b/database/base.rb
new file mode 100644
index 0000000..81cbc04
--- /dev/null
+++ b/database/base.rb
@@ -0,0 +1,13 @@
+class SdAdmin::Database::Base
+
+  def initialize
+    @data = Hash.new
+  end
+
+  def _create(data)
+  end
+
+  def _read(id)
+  end
+
+end
diff --git a/database/factory.rb b/database/factory.rb
new file mode 100644
index 0000000..96ecacb
--- /dev/null
+++ b/database/factory.rb
@@ -0,0 +1,3 @@
+class SdAdmin::Database::Factory
+
+end
diff --git a/database/ldap.rb b/database/ldap.rb
new file mode 100644
index 0000000..2bbde01
--- /dev/null
+++ b/database/ldap.rb
@@ -0,0 +1,53 @@
+class SdAdmin::Database::Ldap
+  attr_writer :base_dn, :mapper
+
+  def initialize(args = {})
+    @con = {:host => 'host.one.virtual', :port => 389}
+
+    @con[:host] = args[:host] if args[:host]
+    @con[:port] = args[:port] if args[:port]
+
+    @base_dn = args[:base_dn] if args[:base_dn]
+
+    @ldap  = Net::LDAP.new(@con)
+    filter = args[:filter] if args[:filter]
+  end
+
+  def filter=(filter)
+    @filter = Net::LDAP::Filter::construct(filter)
+  end
+
+  def each
+    _load.each{|key,entry| puts "DEBUG: #{key}"; yield key,entry}
+  end
+
+  def [](id)
+    _load[id]
+  end
+
+  def []=(id, data)
+  end
+
+  def insert(data)
+  end
+
+  def delete(id)
+  end
+
+  private
+
+  def _load!
+    @data = Hash.new
+    @ldap.search(:base => @base_dn, :filter => @filter) do |entry|
+      attributes = Hash.new
+      entry.each{|attr,value| attributes.merge!({attr => value})}
+      @data.merge!({attributes[:dn][0] => attributes})
+    end
+  end
+
+  def _load
+    _load! if ! @data
+    @data
+  end
+
+end
diff --git a/loader/user.rb b/loader/user.rb
new file mode 100644
index 0000000..e69de29
diff --git a/mappers/ldap.rb b/mappers/ldap.rb
new file mode 100644
index 0000000..a660087
--- /dev/null
+++ b/mappers/ldap.rb
@@ -0,0 +1,197 @@
+  require 'active_support/secure_random'
+  require 'net/ldap'
+
+  class SystemDataBackendLdap
+
+    LDAP_USER_MAP = {
+      :uid           => :name,
+      :userpassword  => :pass,
+      :uidnumber     => :uid,
+      :gidnumber     => :gid,
+      :loginshell    => :shell,
+      :homedirectory => :home
+    }
+
+    LDAP_GROUP_MAP = {
+      :cn        => :name,
+      :gidnumber => :gid,
+      :memberuid => :members
+    }
+
+    LDAP_MAILALIASPERSON_MAP = {
+      :sn => :surname,
+      :cn => :name
+    }
+
+    LDAP_MAP = {
+      :User            => LDAP_USER_MAP,
+      :Group           => LDAP_GROUP_MAP,
+      :Site            => { :o => :name },
+      :MailAliasRole   => { :cn => :user },
+      :MailAliasPerson => LDAP_MAILALIASPERSON_MAP,
+      :mailAccount     => { :homedirectory => :home }
+    }
+
+    LDAP_FILTER = {
+      :User            => '(objectClass=posixAccount)',
+      :Group           => '(objectClass=posixGroup)',
+      :Site            => '(&(objectClass=organization)(!(o=hosting)))',
+      :MailAliasRole   => '(&(objectClass=MailAlias)(objectClass=organizationalrole))',
+      :MailAliasPerson => '(&(objectClass=MailAlias)(objectClass=person))',
+      :MailAccount     => '(objectClass=mailAccount)'
+    }
+
+    LDAP_OBJECTCLASS = {
+      :User            => [ 'account', 'posixAccount', 'shadowAccount' ],
+      :Group           => 'posixGroup',
+      :Site            => 'organization',
+      :MailAliasRole   => [ 'organizationalRole', 'MailAlias' ],
+      :MailAliasPerson => [ 'person', 'MailAlias' ],
+      :MailAccount     => [ 'person', 'MailAccount' ]
+    }
+
+    LDAP_LAMBDA_USER = lambda do |entry|
+      entry[:cn] = entry[:uid]
+      entry[:shadowlastchange] = (Time::now.to_i/60/60/24).to_s
+      entry[:replace] += ['shadowreplace'] if entry[:replace]
+    end
+
+    LDAP_LAMBDA = {
+      :User => LDAP_LAMBDA_USER
+    }
+
+    def initialize(host, port, baseDn, args={})
+      @baseDn    = baseDn
+      @systemDn  = 'o=system,' + @baseDn
+      @hostingDn = 'o=hosting,' + @baseDn
+
+      @systemDn  = args[:systemDn] if args[:systemDn]
+      @hostingDn = args[:hostingDn] if args[:hostingDn]
+
+      @ldap      = Net::LDAP.new(:host => host, :port => port)
+      @ldapData  = Hash.new
+    end
+
+    def load!(kind)
+      @ldapData[kind] = Hash.new if ! @ldapData[kind]
+
+      @ldapData[kind][:int] = @ldap.search(
+        :base   => ldapBase(kind),
+        :filter => Net::LDAP::Filter::construct(LDAP_FILTER[kind])
+      )
+    end
+
+    def load(kind)
+      load!(kind) if ! @ldapData[kind]
+
+      @ldapData[kind][:ext] = @ldapData[kind][:int].map do |data|
+        map = { :dn => :id }
+        map.merge!(LDAP_MAP[kind]) if LDAP_MAP[kind]
+
+        ydata = {}
+        data.each do |key,value|
+          ydata.merge!({ map[key] || key => value.size==1?value[0]:value.to_a })
+        end
+        ydata
+      end if ! @ldapData[kind][:ext] && @ldapData[kind][:int]
+
+      @ldapData[kind][:ext].each{|ydata| yield ydata} if @ldapData[kind][:ext]
+  end
+
+  def update(kind, data)
+    map = {}
+    map.merge!(LDAP_MAP[kind].invert) if LDAP_MAP[kind]
+
+    odata = @ldapData[kind][:ext].find{|edata| edata[:id] == data[:id]}
+
+    data.each do |key,value| 
+      pat_key = map[key] ? map[key] : key
+      if odata[:id] =~ /(^|, *)#{pat_key.to_s}=([^, ]+)/ && $2 != value
+        return replace(kind, data)
+      end
+    end
+
+    entry = Net::LDAP::Entry.new(data[:id])
+    data = data.find_all{|key,value| value != odata[key]}
+    data.delete(:id)
+
+    replace = Array.new
+    data.each do |key,value|
+      key = map[key] if map[key]
+      replace.push(key.to_s)
+      entry[key] = value
+    end
+
+    if replace.empty?
+      puts 'INFO: no changes'
+    else
+      entry[:changetype]  = 'modify'
+      entry[:replace]     = replace
+      LDAP_LAMBDA[kind].call(entry) if LDAP_LAMBDA[kind]
+
+      puts entry.to_ldif
+    end
+  end
+
+  def replace(kind, data)
+    puts 'INFO: do replace'
+    puts '----------------'
+    odata = @ldapData[kind][:ext].find{|edata| edata[:id] == data[:id]}
+    delete(odata)
+    puts
+    insert(kind, data)
+    puts '----------------'
+  end
+
+  def delete(data)
+    entry = Net::LDAP::Entry.new(data[:id])
+    entry[:changetype] = 'delete'
+
+    puts entry.to_ldif
+  end
+
+  def insert(kind, data)
+    map = {}
+    map.merge!(LDAP_MAP[kind].invert) if LDAP_MAP[kind]
+
+    data.delete(:id)
+    entry = Net::LDAP::Entry.new(ldapDn(kind, data))
+    entry[:changetype]  = 'add'
+    entry[:objectclass] = LDAP_OBJECTCLASS[kind]
+
+    data.each do |key,value|
+      key = map[key] if map[key]
+      entry[key] = value
+    end
+    LDAP_LAMBDA[kind].call(entry) if LDAP_LAMBDA[kind]
+
+    puts entry.to_ldif
+  end
+
+  private
+
+  def ldapBase(kind)
+    case(kind)
+    when :User, :Group: @systemDn
+    when :Site, :MailAliasRole, :MailAliasPerson, :MailAccount: @hostingDn
+    end
+  end
+
+  def ldapDn(kind, data)
+    case(kind)
+    when :User
+      "uid=#{data[:name]},ou=user,#{ldapBase(kind)}"
+    when :Group
+      "cn=#{data[:name]},ou=group,#{ldapBase(kind)}"
+    when :Site
+      "o=#{data[:name]},#{ldapBase(kind)}"
+    when :MailAliasRole
+      "cn=#{data[:user]},o=#{data[:mail].sub(/.*@/, '')},#{ldapBase(kind)}"
+    when :MailAliasPerson
+      "mail=#{data[:mail]},o=#{data[:mail].sub(/.*@/, '')},#{ldapBase(kind)}"
+    when :MailAccount
+      "mail=#{data[:mail]},o=#{data[:mail].sub(/.*@/, '')},#{ldapBase(kind)}"
+    end
+  end
+
+end
diff --git a/model.rb b/model.rb
new file mode 100644
index 0000000..37a1e26
--- /dev/null
+++ b/model.rb
@@ -0,0 +1,16 @@
+module SdAdmin::Model
+	module Interface
+	end
+
+	class Base
+		require 'model/interface'
+		require 'database'
+		include SdAdmin::Model::Interface
+	end
+
+	class User < Base
+	end
+
+	require 'model/base'
+	require 'model/user'
+end
diff --git a/model/base.rb b/model/base.rb
new file mode 100644
index 0000000..2569a41
--- /dev/null
+++ b/model/base.rb
@@ -0,0 +1,9 @@
+class SdAdmin::Model::Base
+	attr_reader :backend
+
+	def initialize(backend)
+		@backend = SdAdmin::Database::Ldap.new
+		@backend = backend if backend
+	end
+
+end
diff --git a/model/group.rb b/model/group.rb
new file mode 100644
index 0000000..e607420
--- /dev/null
+++ b/model/group.rb
@@ -0,0 +1,14 @@
+require 'SystemData'
+
+class Group < SystemData
+  attr_accessor :name, :gid, :members
+  
+  def initialize(args = {})
+		super(args)
+
+    @name    = args[:name]
+    @gid     = args[:gid]
+    @members = args[:members]
+		@members = Array.new if @members.nil?
+  end
+end
diff --git a/model/interface.rb b/model/interface.rb
new file mode 100644
index 0000000..25de225
--- /dev/null
+++ b/model/interface.rb
@@ -0,0 +1,7 @@
+module SdAdmin::Model::Interface
+
+	def all
+		Hash[self.backend.map{|key,entry| [key, entry]}]
+	end
+
+end
diff --git a/model/mail_account.rb b/model/mail_account.rb
new file mode 100644
index 0000000..a6ec9fd
--- /dev/null
+++ b/model/mail_account.rb
@@ -0,0 +1,17 @@
+require 'SystemData'
+
+class MailAccount < SystemData
+  attr_accessor :mail, :mailbox
+
+	def initialize(args = {})
+		super(args)
+
+		@mail     = args[:mail]
+		@home     = args[:home]
+		@mailbox  = args[:mailbox]
+	end
+
+	def site
+		@mail.sub(/.*@/, '')
+	end
+end
diff --git a/model/mail_alias_person.rb b/model/mail_alias_person.rb
new file mode 100644
index 0000000..e4308ce
--- /dev/null
+++ b/model/mail_alias_person.rb
@@ -0,0 +1,18 @@
+require 'SystemData'
+
+class MailAliasPerson < SystemData
+  attr_accessor :mail, :maildrop, :surname, :name
+
+	def initialize(args = {})
+    super(args)
+
+		@mail     = args[:mail]
+		@maildrop = args[:maildrop]
+		@surname  = args[:surname]
+		@name     = args[:name]
+	end
+
+	def site
+		@mail.sub(/.*@/, '')
+	end
+end
diff --git a/model/mail_alias_role.rb b/model/mail_alias_role.rb
new file mode 100644
index 0000000..c16b474
--- /dev/null
+++ b/model/mail_alias_role.rb
@@ -0,0 +1,17 @@
+require 'SystemData'
+
+class MailAliasRole < SystemData
+  attr_accessor :mail, :maildrop, :user
+
+	def initialize(args = {})
+    super(args)
+
+		@mail     = args[:mail]
+		@maildrop = args[:maildrop]
+		@user     = args[:user]
+	end
+
+	def site
+		@mail.sub(/.*@/, '')
+	end
+end
diff --git a/model/site.rb b/model/site.rb
new file mode 100644
index 0000000..133ccbe
--- /dev/null
+++ b/model/site.rb
@@ -0,0 +1,11 @@
+require 'SystemData'
+
+class Site < SystemData
+	attr_accessor :name
+
+	def initialize(args = {})
+		super(args)
+
+		@name = args[:name]
+	end
+end
diff --git a/model/system_data.rb b/model/system_data.rb
new file mode 100644
index 0000000..ec1652b
--- /dev/null
+++ b/model/system_data.rb
@@ -0,0 +1,24 @@
+class SystemData
+	attr_reader :id
+
+	def initialize(args = {})
+		@backend = args[:backend]
+		@id      = args[:id]
+	end
+
+	def save
+    kind = self.class.to_s.to_sym
+
+		if @id
+			@backend.update(kind, to_h)
+		else
+			@backend.insert(kind, to_h)
+		end
+	end
+
+	def to_h
+		Hash[instance_variables.map do |var|
+			[var[1...var.size].to_sym, eval(var)] if var != '@backend'
+		end]
+	end
+end
diff --git a/model/user.rb b/model/user.rb
new file mode 100644
index 0000000..6b9f126
--- /dev/null
+++ b/model/user.rb
@@ -0,0 +1,19 @@
+class SdAdmin::Model::User
+	attr_accessor :name, :pass, :uid, :gid, :shell, :home
+
+	def initialize(args={}, backend=nil)
+		super(backend)
+
+		@backend.base_dn = 'ou=user,o=system,dc=weird-web-workers,dc=org'
+		@backend.filter  = '(objectClass=posixAccount)'
+
+		@name          = args[:name]
+		@pass          = args[:pass]
+		@uid           = args[:uid]
+		@gid           = args[:gid]
+		@shell         = args[:shell]
+		@home          = args[:home]
+		@shadowmax     = args[:shadowmax]
+		@shadowwarning = args[:shadowwarning]
+	end
+end
diff --git a/sd_admin.rb b/sd_admin.rb
new file mode 100644
index 0000000..30de395
--- /dev/null
+++ b/sd_admin.rb
@@ -0,0 +1,10 @@
+module SdAdmin
+  module Model
+  end
+  
+  module Database
+  end
+
+  require 'model'
+  require 'database'
+end
diff --git a/test_dummy2.rb b/test_dummy2.rb
new file mode 100644
index 0000000..6fa5b7a
--- /dev/null
+++ b/test_dummy2.rb
@@ -0,0 +1,5 @@
+require 'sd_admin'
+
+user = SdAdmin::Model::User.new
+
+puts user.all.inspect