diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d964a1f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+pkg
+*.gem
+*.gemspec
+rdoc
+*.rbc
diff --git a/README.md b/README.md
index 67ed7aa..7459cc5 100644
--- a/README.md
+++ b/README.md
@@ -1,14 +1,14 @@
 Dependencies
 ============
 
-You need first the [Bdb](http://github.com/DenisKnauf/bdb) and of course [ruby](http://ruby-lang.org).
+You need first the [Bdb](http://github.com/ruby-bdb/bdb) and of course [ruby](http://ruby-lang.org).
 
 Download
 ========
 
 via git:
 
-	git clone git://github.com/DenisKnauf/sbdb.git
+	git clone git://github.com/ruby-bdb/sbdb
 
 Install
 =======
@@ -23,21 +23,22 @@ First, open environment and database
 
 	require 'sbdb'
 	Dir.mkdir 'newenv'  rescue Errno::EEXIST
-	env = SBDB::Env.new 'newenv', SBDB::CREATE
-	db = env.open SBDB::Btree, 'newdb.db', :flags => SBDB::CREATE
+	env = SBDB::Env.new 'newenv', SBDB::CREATE | SBDB::Env::INIT_TRANSACTION
+	db = env.btree 'newdb.db', :flags => SBDB::CREATE
 
 It works nearly like a Ruby-Hash:
 
 	db['key'] = 'value'
-	db['key']		# => 'value'
-	db.to_hash		# => {'key'=>'value'}
-	db.map {|k, v| [k, v].join ' => '}		# => ["key => value"]
-	db.count		# => 1
+	db['key']   # => 'value'
+	db.to_hash  # => {'key'=>'value'}
+	db.map {|k, v| "k => v" } # => ["key => value"]
+	db.count    # => 1
+	db.each {|k,v| puts "#{k}: #{v}" }
 
-SBDB::DB#each uses a SBDB::Cursor:
+`SBDB::DB#each` uses a `SBDB::Cursor`:
 
 	cursor = db.cursor
-	cursor.each {|k,v| puts "#{k}: ${v}" }
+	cursor.each {|k,v| puts "#{k}: #{v}" }
 
 **Don't forget to close everything, you've opened!**
 
@@ -47,10 +48,14 @@ SBDB::DB#each uses a SBDB::Cursor:
 
 But you can use a *lambda* to ensure to close everything:
 
-	SBDB::Env.new( 'newenv', SBDB::CREATE) do |env|
+	SBDB::Env.new( 'newenv', SBDB::CREATE | SBDB::Env::INIT_TRANSACTION) do |env|
 		env.open SBDB::Btree, 'newdb.db', :flags => SBDB::CREATE do |db|
 			db.to_hash
 		end
 	end
 
-SBDB::DB#to_hash creates a cursor and close it later.
+`SBDB::DB#to_hash` creates a cursor and close it later.
+
+Tip:
+
+	Signal.trap 'EXIT', env.method( :close)
diff --git a/Rakefile b/Rakefile
index 2804098..89416e7 100644
--- a/Rakefile
+++ b/Rakefile
@@ -10,11 +10,12 @@ begin
     gem.summary = %Q{Simple Ruby Berkeley DB}
     gem.description = %Q{Simple Ruby Berkeley DB wrapper library for bdb.}
     gem.email = "Denis.Knauf@gmail.com"
-    gem.homepage = "http://github.com/DenisKnauf/bdb"
+    gem.homepage = "http://github.com/ruby-bdb/sbdb"
     gem.authors = ["Denis Knauf"]
     gem.files = %w[AUTHORS README.md VERSION lib/**/*.rb test/**/*.rb]
     gem.require_paths = %w[lib]
-		gem.add_dependency 'dk-bdb'
+		gem.add_dependency 'bdb', '>= 0.2.6.5'
+		gem.add_dependency 'ref'
   end
   Jeweler::GemcutterTasks.new
 rescue LoadError
diff --git a/VERSION b/VERSION
index 7c1886b..7e743eb 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.0.10
+0.0.12.2
\ No newline at end of file
diff --git a/lib/sbdb.rb b/lib/sbdb.rb
index d796a06..2b3ab6f 100644
--- a/lib/sbdb.rb
+++ b/lib/sbdb.rb
@@ -1,4 +1,5 @@
 require 'bdb'
+require 'ref'
 require 'sbdb/environment'
 require 'sbdb/db'
 require 'sbdb/cursor'
diff --git a/lib/sbdb/db.rb b/lib/sbdb/db.rb
index 2da1a94..2a0d04a 100644
--- a/lib/sbdb/db.rb
+++ b/lib/sbdb/db.rb
@@ -60,7 +60,11 @@ module SBDB
 
 		def _txn txn
 			txn ||= @txn
-			txn && t.bdb_object
+			txn && txn.bdb_object
+		end
+
+		def transaction flg = nil, &exe
+			block_given? ? home.transaction( flg, &exe) : home.transaction( flg)
 		end
 
 		# Arguments:
diff --git a/lib/sbdb/environment.rb b/lib/sbdb/environment.rb
index 9a6479e..71f5ef9 100644
--- a/lib/sbdb/environment.rb
+++ b/lib/sbdb/environment.rb
@@ -1,5 +1,4 @@
 require 'bdb'
-require 'sbdb/weakhash'
 require 'sbdb/db'
 require 'sbdb/transaction'
 
@@ -61,7 +60,7 @@ module SBDB
 		def initialize *args
 			opts = ::Hash === args.last ? args.pop : {}
 			opts = {:dir => args[0], :flags => args[1], :mode => args[2]}.update opts
-			@dbs, @env = WeakHash.new, Bdb::Env.new( 0)
+			@dbs, @env = Ref::WeakValueMap.new, Bdb::Env.new( 0)
 			@env.log_config opts[:log_config], 1  if opts[:log_config]
 			@env.lg_bsize = opts[:lg_bsize]  if opts[:lg_bsize]
 			@env.lg_max = opts[:lg_max]  if opts[:lg_max]
diff --git a/lib/sbdb/weakhash.rb b/lib/sbdb/weakhash.rb
deleted file mode 100644
index f6e9d9c..0000000
--- a/lib/sbdb/weakhash.rb
+++ /dev/null
@@ -1,61 +0,0 @@
-module SBDB
-
-# See http://eigenclass.org/hiki/deferred-finalizers-in-Ruby
-# Not threadsafe.
-
-class WeakHash
-	attr_reader :cache
-	def initialize cache = ::Hash.new
-		@cache = cache
-		@key_map = {}
-		@rev_cache = ::Hash.new{|h,k| h[k] = {}}
-		@reclaim_value = lambda do |value_id| 
-			if @rev_cache.has_key? value_id
-				@rev_cache[value_id].each_key{|key| @cache.delete key}
-				@rev_cache.delete value_id
-			end
-		end
-		@reclaim_key = lambda do |key_id|
-			@cache.delete @key_map.delete(key_id)  if @key_map.has_key? key_id
-		end
-	end
-
-	def []= key, value
-		case key
-		when Fixnum, Symbol, true, false
-			key2 = key
-		else
-			key2 = key.dup
-		end
-		@rev_cache[value.object_id][key2] = true
-		@cache[key2] = value.object_id
-		@key_map[key.object_id] = key2
-
-		ObjectSpace.define_finalizer(value, @reclaim_value)
-		ObjectSpace.define_finalizer(key, @reclaim_key)
-		value
-	end
-
-	def [] key
-		value_id = @cache[key]
-		return ObjectSpace._id2ref( value_id)  unless value_id.nil?
-		nil
-	rescue RangeError
-		nil
-	end
-
-	def each &e
-		@cache.each do |k, vid|
-			unless vid.nil?
-				obj = begin
-						ObjectSpace._id2ref vid
-					rescue RangeError
-						next
-					end
-				yield k, obj
-			end
-		end
-	end
-end
-
-end
diff --git a/sbdb.gemspec b/sbdb.gemspec
deleted file mode 100644
index 612d59b..0000000
--- a/sbdb.gemspec
+++ /dev/null
@@ -1,48 +0,0 @@
-# Generated by jeweler
-# DO NOT EDIT THIS FILE DIRECTLY
-# Instead, edit Jeweler::Tasks in Rakefile, and run 'rake gemspec'
-# -*- encoding: utf-8 -*-
-
-Gem::Specification.new do |s|
-  s.name = %q{sbdb}
-  s.version = "0.0.10"
-
-  s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
-  s.authors = ["Denis Knauf"]
-  s.date = %q{2011-08-01}
-  s.description = %q{Simple Ruby Berkeley DB wrapper library for bdb.}
-  s.email = %q{Denis.Knauf@gmail.com}
-  s.extra_rdoc_files = [
-    "LICENSE",
-    "README.md"
-  ]
-  s.files = [
-    "AUTHORS",
-    "README.md",
-    "VERSION",
-    "lib/sbdb.rb",
-    "lib/sbdb/cursor.rb",
-    "lib/sbdb/db.rb",
-    "lib/sbdb/environment.rb",
-    "lib/sbdb/transaction.rb",
-    "lib/sbdb/weakhash.rb"
-  ]
-  s.homepage = %q{http://github.com/DenisKnauf/bdb}
-  s.require_paths = ["lib"]
-  s.rubygems_version = %q{1.3.7}
-  s.summary = %q{Simple Ruby Berkeley DB}
-
-  if s.respond_to? :specification_version then
-    current_version = Gem::Specification::CURRENT_SPECIFICATION_VERSION
-    s.specification_version = 3
-
-    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0') then
-      s.add_runtime_dependency(%q<dk-bdb>, [">= 0"])
-    else
-      s.add_dependency(%q<dk-bdb>, [">= 0"])
-    end
-  else
-    s.add_dependency(%q<dk-bdb>, [">= 0"])
-  end
-end
-