diff --git a/Gemfile b/Gemfile
index 161595d..c241da4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,3 +2,4 @@ source 'https://rubygems.org'
 gem 'ffi'
 gem 'sqlite3'
 gem 'rake-compiler'
+gem 'rake-extensions'
diff --git a/README.adoc b/README.adoc
new file mode 100644
index 0000000..43d1494
--- /dev/null
+++ b/README.adoc
@@ -0,0 +1,19 @@
+duperemove(rb)
+==============
+
+Replaces `duperemove`s dedupe-functionality.
+It is an own program, which uses the database like `duperemove`.
+While `duperemove` scans directories and builds database, this program only dedupes files extents.
+
+The advantage is, duperemoverb allowes incremental/partial deduplications.
+While duperemove deduplicates any files registered in database, you can give a path, which files to deduplicate.
+Files outside this path will be ignored, but will be deduplicated, if it shares same digests like extends of file inside this path.
+
+Partial deduplication
+---------------------
+
+* /a/1 has two extents: 0x12, 0x54
+* /b/1 has two extents: 0x54, 0xa8
+* /b/2 has two extents: 0x90, 0xa8
+
+If you call `duperemoverb dedupe /a`, `/b/1` and `/b/2` will be ignored, but the first extent of `/b/1` will be deduplicated with `/a/1` second extent.
diff --git a/Rakefile b/Rakefile
index 489e109..afc57ac 100644
--- a/Rakefile
+++ b/Rakefile
@@ -4,18 +4,26 @@ require 'rake'
 require 'rake/extensiontask'
 require 'bundler'
 
-Rake::ExtensionTask.new( "deduperemoverb") do |extension|
-	extension.lib_dir = "ext"
+extensions = %w[fideduperange].map {|n| [n, Pathname.new( 'ext') + n + "#{n}.so"] }.to_h
+
+extensions.each do |name, path|
+	Rake::ExtensionTask.new name do |extension|
+		extension.lib_dir = path.dirname
+	end
 end
 
 task :chmod do
-	File.chmod 0775, 'ext/deduperemoverb.so'
+	extensions.each do |_,path|
+		path.chmod 0755
+	end
 end
 
 task :clean do
-	File.unlink 'ext/deduperemoverb.so'  if File.exists? 'ext/deduperemoverb.so'
+	extensions.each do |_,path|
+		path.unlink  if path.exist?
+	end
 end
 
 task :build => [:clean, :compile, :chmod]
 
-Bundler::GemHelper.install_tasks name: 'deduperemoverb'
+Bundler::GemHelper.install_tasks name: 'duperemoverb'
diff --git a/bin/deduperemoverb b/bin/duperemoverb
similarity index 98%
rename from bin/deduperemoverb
rename to bin/duperemoverb
index ab4fdde..0c5ef11 100755
--- a/bin/deduperemoverb
+++ b/bin/duperemoverb
@@ -2,7 +2,7 @@
 # vim: set noet sw=2 ts=2 sts=2:
 
 require 'dencli'
-require 'deduperemoverb'
+require 'duperemoverb'
 require 'ostruct'
 require 'logger'
 
diff --git a/deduperemoverb.gemspec b/duperemoverb.gemspec
similarity index 65%
rename from deduperemoverb.gemspec
rename to duperemoverb.gemspec
index 81c671e..4b397ad 100644
--- a/deduperemoverb.gemspec
+++ b/duperemoverb.gemspec
@@ -1,14 +1,14 @@
 # vim: set noet sw=2 ts=2 sts=2:
 require 'rake'
-require_relative 'lib/deduperemoverb/version'
+require_relative 'lib/duperemoverb/version'
 
 Gem::Specification.new do |s|
-	s.name = 'deduperemoverb'
+	s.name = 'duperemoverb'
 	s.version = Duperemove::VERSION
 	s.licenses = %w[LGPLv3]
 	s.authors = 'Denis Knauf'
-	s.homepage = 'https://git.denkn.at/deac/deduperemoverb'
-	s.summary = 'Deduplication of file junks of found files by deduperemove.'
+	s.homepage = 'https://git.denkn.at/deac/duperemoverb'
+	s.summary = 'Deduplication of file junks of found files by duperemove.'
 	s.files =
 		FileList[ %w[
 			lib/**/*.rb
@@ -17,9 +17,9 @@ Gem::Specification.new do |s|
 			ext/*/*.c  ext/*/extconf.rb
 		]]
 	s.bindir = %w[bin]
-	s.executables << 'deduperemoverb'
+	s.executables << 'duperemoverb'
 	s.require_paths = %w[lib]
-	s.extensions = %w[ext/deduperemoverb/extconf.rb]
+	s.extensions = %w[ext/fideduperange/extconf.rb]
 
 	s.add_development_dependency "rake", "~> 13"
 	s.add_dependency "ffi", '~> 1.15'
diff --git a/ext/deduperemoverb/extconf.rb b/ext/deduperemoverb/extconf.rb
deleted file mode 100644
index 6901457..0000000
--- a/ext/deduperemoverb/extconf.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-require "mkmf"
-
-create_makefile "deduperemoverb"
diff --git a/ext/fideduperange/extconf.rb b/ext/fideduperange/extconf.rb
new file mode 100644
index 0000000..89c1ccd
--- /dev/null
+++ b/ext/fideduperange/extconf.rb
@@ -0,0 +1,3 @@
+require "mkmf"
+
+create_makefile "fideduperange"
diff --git a/ext/deduperemoverb/deduperemoverb.c b/ext/fideduperange/fideduperange.c
similarity index 100%
rename from ext/deduperemoverb/deduperemoverb.c
rename to ext/fideduperange/fideduperange.c
diff --git a/lib/deduperemoverb.rb b/lib/duperemoverb.rb
similarity index 99%
rename from lib/deduperemoverb.rb
rename to lib/duperemoverb.rb
index 247ab35..4b09a78 100755
--- a/lib/deduperemoverb.rb
+++ b/lib/duperemoverb.rb
@@ -4,7 +4,7 @@
 require 'sqlite3'
 require 'pathname'
 require 'ostruct'
-require 'deduperemoverb/file_dedupe_range'
+require 'duperemoverb/file_dedupe_range'
 
 class SQLite3::ResultSet
 	def each_enum
diff --git a/lib/deduperemoverb/file_dedupe_range.rb b/lib/duperemoverb/file_dedupe_range.rb
similarity index 98%
rename from lib/deduperemoverb/file_dedupe_range.rb
rename to lib/duperemoverb/file_dedupe_range.rb
index c026ae5..4814b94 100644
--- a/lib/deduperemoverb/file_dedupe_range.rb
+++ b/lib/duperemoverb/file_dedupe_range.rb
@@ -15,7 +15,7 @@ module FileDedupeRange
 	extend FFI::Library
 	ffi_lib Pathname.new( __FILE__).
 		dirname.dirname.dirname.
-		join( *%w[ext deduperemoverb deduperemoverb.so]).
+		join( *%w[ext fideduperange fideduperange.so]).
 		expand_path.
 		to_s
 
diff --git a/lib/deduperemoverb/version.rb b/lib/duperemoverb/version.rb
similarity index 52%
rename from lib/deduperemoverb/version.rb
rename to lib/duperemoverb/version.rb
index 39bfe4c..2029198 100644
--- a/lib/deduperemoverb/version.rb
+++ b/lib/duperemoverb/version.rb
@@ -1,3 +1,3 @@
 class Duperemove
-	VERSION = '0.0.2'
+	VERSION = '0.0.3'
 end