diff --git a/README.md b/README.md
index baf3091..436a421 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ options:
     -f, --run-control PATH           specify alternate run control file
     -r, --require PATH               require ruby feature
     -l, --layout LAYOUT              specify layout
+    -w, --worker WORKER              specify worker
 ```
 
 
diff --git a/features/cli/worker.feature b/features/cli/worker.feature
new file mode 100644
index 0000000..94162e7
--- /dev/null
+++ b/features/cli/worker.feature
@@ -0,0 +1,9 @@
+Feature: worker CLI option
+
+  Scenario: uses the blocking worker when `block' is given
+    When I run uhwm with option -v -w block
+    Then the output must match /work.+event.+block/i
+
+  Scenario: uses the multiplexing worker when `mux' is given
+    When I run uhwm with option -v -w mux
+    Then the output must match /work.+event.+mux/i
diff --git a/features/run_control/worker.feature b/features/run_control/worker.feature
new file mode 100644
index 0000000..a586c5a
--- /dev/null
+++ b/features/run_control/worker.feature
@@ -0,0 +1,9 @@
+Feature: `worker' run control keyword
+
+  Scenario: configures the modifier key
+    Given a run control file with:
+      """
+      worker :mux
+      """
+    And I start uhwm
+    Then the output must match /work.+event.+mux/i
diff --git a/features/steps/output_steps.rb b/features/steps/output_steps.rb
index 73cd67f..875bf1a 100644
--- a/features/steps/output_steps.rb
+++ b/features/steps/output_steps.rb
@@ -9,6 +9,7 @@ options:
     -f, --run-control PATH           specify alternate run control file
     -r, --require PATH               require ruby feature
     -l, --layout LAYOUT              specify layout
+    -w, --worker WORKER              specify worker
   eoh
 end
 
diff --git a/lib/uh/wm.rb b/lib/uh/wm.rb
index c3c6f0c..0614a84 100644
--- a/lib/uh/wm.rb
+++ b/lib/uh/wm.rb
@@ -12,6 +12,10 @@ require 'uh/wm/logger_formatter'
 require 'uh/wm/manager'
 require 'uh/wm/run_control'
 require 'uh/wm/runner'
+require 'uh/wm/workers'
+require 'uh/wm/workers/base'
+require 'uh/wm/workers/blocking'
+require 'uh/wm/workers/mux'
 
 module Uh
   module WM
diff --git a/lib/uh/wm/cli.rb b/lib/uh/wm/cli.rb
index 8853582..12631d9 100644
--- a/lib/uh/wm/cli.rb
+++ b/lib/uh/wm/cli.rb
@@ -77,6 +77,11 @@ module Uh
           opts.on '-l', '--layout LAYOUT', 'specify layout' do |layout|
             @env.layout_class = self.class.const_get layout.to_sym
           end
+
+          opts.on '-w', Workers.types, '--worker WORKER',
+            'specify worker' do |worker|
+            @env.worker = worker.to_sym
+          end
         end
       end
     end
diff --git a/lib/uh/wm/env.rb b/lib/uh/wm/env.rb
index 2bb63aa..7417647 100644
--- a/lib/uh/wm/env.rb
+++ b/lib/uh/wm/env.rb
@@ -3,10 +3,11 @@ module Uh
     class Env
       RC_PATH = '~/.uhwmrc.rb'.freeze
 
-      MODIFIER = :mod1
-      KEYBINDS = {
+      MODIFIER  = :mod1
+      KEYBINDS  = {
         q: proc { quit }
       }.freeze
+      WORKER    = :block
 
       LOGGER_LEVEL          = Logger::WARN
       LOGGER_LEVEL_VERBOSE  = Logger::INFO
@@ -20,13 +21,15 @@ module Uh
       def_delegator :@output, :print
 
       attr_reader   :output, :keybinds
-      attr_accessor :verbose, :debug, :rc_path, :layout_class, :modifier
+      attr_accessor :verbose, :debug, :rc_path, :layout_class, :modifier,
+                    :worker
 
       def initialize output
         @output   = output
         @rc_path  = RC_PATH
         @modifier = MODIFIER
         @keybinds = KEYBINDS.dup
+        @worker   = :block
       end
 
       def verbose?
diff --git a/lib/uh/wm/manager.rb b/lib/uh/wm/manager.rb
index 5fb9089..d5c6b0b 100644
--- a/lib/uh/wm/manager.rb
+++ b/lib/uh/wm/manager.rb
@@ -16,6 +16,10 @@ module Uh
         @clients  = []
       end
 
+      def to_io
+        IO.new(@display.fileno)
+      end
+
       def connect
         @events.emit :connecting, args: @display
         @display.open
@@ -31,12 +35,20 @@ module Uh
         @events.emit :disconnected
       end
 
+      def flush
+        @display.flush
+      end
+
       def grab_key keysym, mod = nil
         mod_mask = KEY_MODIFIERS[@modifier]
         mod_mask |= KEY_MODIFIERS[mod] if mod
         @display.grab_key keysym.to_s, mod_mask
       end
 
+      def handle_next_event
+        handle @display.next_event
+      end
+
       def handle_pending_events
         handle @display.next_event while @display.pending?
       end
diff --git a/lib/uh/wm/run_control.rb b/lib/uh/wm/run_control.rb
index 2d511be..b3fc618 100644
--- a/lib/uh/wm/run_control.rb
+++ b/lib/uh/wm/run_control.rb
@@ -32,6 +32,10 @@ module Uh
         @env.keybinds[translate_keysym keysym] = block
       end
 
+      def worker type, **options
+        @env.worker = [type, options]
+      end
+
 
       private
 
diff --git a/lib/uh/wm/runner.rb b/lib/uh/wm/runner.rb
index 2a36744..582869a 100644
--- a/lib/uh/wm/runner.rb
+++ b/lib/uh/wm/runner.rb
@@ -54,8 +54,28 @@ module Uh
         end
       end
 
+      def worker
+        @worker ||= Workers.build(*(@env.worker)).tap do |w|
+          w.on_read do
+            @env.log_debug 'Processing pending events'
+            @manager.handle_pending_events
+          end
+          w.on_read_next do
+            @env.log_debug 'Processing next event'
+            @manager.handle_next_event
+          end
+          w.on_timeout do |*args|
+            @env.log_debug "Worker timeout: #{args.inspect}"
+            @env.log_debug 'Flushing X output buffer'
+            @manager.flush
+          end
+        end
+      end
+
       def run_until &block
-        manager.handle_pending_events until block.call
+        worker.watch @manager
+        @env.log "Working events with `#{worker.class}'"
+        worker.work_events until block.call
       end
 
       def terminate
diff --git a/lib/uh/wm/testing/acceptance_helpers.rb b/lib/uh/wm/testing/acceptance_helpers.rb
index bf5d05b..44612aa 100644
--- a/lib/uh/wm/testing/acceptance_helpers.rb
+++ b/lib/uh/wm/testing/acceptance_helpers.rb
@@ -11,7 +11,10 @@ module Uh
         end
 
         def uhwm_ensure_stop
-          @process and @process.terminate
+          if @process
+            x_key 'alt+q'
+            @process.terminate
+          end
         end
 
         def uhwm_pid
diff --git a/lib/uh/wm/workers.rb b/lib/uh/wm/workers.rb
new file mode 100644
index 0000000..c065293
--- /dev/null
+++ b/lib/uh/wm/workers.rb
@@ -0,0 +1,21 @@
+module Uh
+  module WM
+    module Workers
+      FACTORIES = {
+        block:  ->(options) { Blocking.new(options) },
+        mux:    ->(options) { Mux.new(options) }
+      }.freeze
+
+      class << self
+        def types
+          FACTORIES.keys
+        end
+
+        def build type, **options
+          (FACTORIES[type] or fail ArgumentError, "unknown worker: `#{type}'")
+            .call options
+        end
+      end
+    end
+  end
+end
diff --git a/lib/uh/wm/workers/base.rb b/lib/uh/wm/workers/base.rb
new file mode 100644
index 0000000..2c2e63b
--- /dev/null
+++ b/lib/uh/wm/workers/base.rb
@@ -0,0 +1,31 @@
+module Uh
+  module WM
+    module Workers
+      class Base
+        def initialize **options
+          @ios = []
+        end
+
+        def watch io
+          @ios << io
+        end
+
+        def before_wait &block
+          if block_given? then @before_wait = block else @before_wait end
+        end
+
+        def on_timeout &block
+          if block_given? then @on_timeout = block else @on_timeout end
+        end
+
+        def on_read &block
+          if block_given? then @on_read = block else @on_read end
+        end
+
+        def on_read_next &block
+          if block_given? then @on_read_next = block else @on_read_next end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/uh/wm/workers/blocking.rb b/lib/uh/wm/workers/blocking.rb
new file mode 100644
index 0000000..d6aefc1
--- /dev/null
+++ b/lib/uh/wm/workers/blocking.rb
@@ -0,0 +1,15 @@
+module Uh
+  module WM
+    module Workers
+      class Blocking < Base
+        def work_events
+          #until yield
+          #  @on_events_read_bang.call
+          #end
+          #@on_events_read_bang.call until yield
+          @on_read_next.call
+        end
+      end
+    end
+  end
+end
diff --git a/lib/uh/wm/workers/mux.rb b/lib/uh/wm/workers/mux.rb
new file mode 100644
index 0000000..e940f4e
--- /dev/null
+++ b/lib/uh/wm/workers/mux.rb
@@ -0,0 +1,18 @@
+module Uh
+  module WM
+    module Workers
+      class Mux < Base
+        def initialize timeout: 1
+          super
+          @timeout = timeout
+        end
+
+        def work_events
+          @before_wait.call if @before_wait
+          if res = select(@ios, [], [], @timeout) then @on_read.call res
+          else @on_timeout.call if @on_timeout end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/uh/wm/cli_spec.rb b/spec/uh/wm/cli_spec.rb
index 6bcf551..027546c 100644
--- a/spec/uh/wm/cli_spec.rb
+++ b/spec/uh/wm/cli_spec.rb
@@ -176,6 +176,15 @@ module Uh
           end
         end
 
+        context 'with worker option' do
+          let(:arguments) { %w[-w mux] }
+
+          it 'assigns the worker type in the env' do
+            cli.parse_arguments!
+            expect(cli.env.worker).to eq :mux
+          end
+        end
+
         context 'with invalid option' do
           let(:arguments) { %w[--unknown-option] }
 
diff --git a/spec/uh/wm/env_spec.rb b/spec/uh/wm/env_spec.rb
index 1d157dd..03336a6 100644
--- a/spec/uh/wm/env_spec.rb
+++ b/spec/uh/wm/env_spec.rb
@@ -29,6 +29,10 @@ module Uh
         expect(env.keybinds.keys).to eq %i[q]
       end
 
+      it 'has the blocking worker by default' do
+        expect(env.worker).to eq :block
+      end
+
       describe '#verbose?' do
         context 'when verbose mode is disabled' do
           before { env.verbose = false }
diff --git a/spec/uh/wm/manager_spec.rb b/spec/uh/wm/manager_spec.rb
index 4c498b3..f45d839 100644
--- a/spec/uh/wm/manager_spec.rb
+++ b/spec/uh/wm/manager_spec.rb
@@ -15,6 +15,18 @@ module Uh
         expect(manager.clients).to be_empty
       end
 
+      describe '#to_io', :xvfb do
+        context 'when connected' do
+          before { manager.connect }
+
+          it 'returns an IO object wrapping the display file descriptor' do
+            expect(manager.to_io)
+              .to be_an(IO)
+              .and have_attributes(fileno: display.fileno)
+          end
+        end
+      end
+
       describe '#connect', :xvfb do
         it 'opens the display' do
           expect(manager.display).to receive(:open).and_call_original
@@ -70,6 +82,13 @@ module Uh
         end
       end
 
+      describe '#flush' do
+        it 'flushes the display' do
+          expect(display).to receive :flush
+          manager.flush
+        end
+      end
+
       describe '#grab_key' do
         it 'grabs given key on the display' do
           expect(manager.display)
@@ -87,6 +106,15 @@ module Uh
         end
       end
 
+      describe '#handle_next_event' do
+        it 'handles the next available event on display' do
+          event = double 'event'
+          allow(display).to receive(:next_event) { event }
+          expect(manager).to receive(:handle).with(event).once
+          manager.handle_next_event
+        end
+      end
+
       describe '#handle_pending_events' do
         let(:event) { double 'event' }
 
diff --git a/spec/uh/wm/run_control_spec.rb b/spec/uh/wm/run_control_spec.rb
index 7684b8e..1afca27 100644
--- a/spec/uh/wm/run_control_spec.rb
+++ b/spec/uh/wm/run_control_spec.rb
@@ -80,6 +80,18 @@ module Uh
           expect(env.keybinds.keys).to include %i[f shift]
         end
       end
+
+      describe '#worker' do
+        it 'sets the worker type in the env' do
+          rc.worker :some_worker
+          expect(env.worker[0]).to eq :some_worker
+        end
+
+        it 'sets the worker options in the env' do
+          rc.worker :some_worker, some: :option
+          expect(env.worker[1]).to eq({ some: :option })
+        end
+      end
     end
   end
 end
diff --git a/spec/uh/wm/runner_spec.rb b/spec/uh/wm/runner_spec.rb
index a2f82aa..bda4bef 100644
--- a/spec/uh/wm/runner_spec.rb
+++ b/spec/uh/wm/runner_spec.rb
@@ -122,11 +122,37 @@ module Uh
         end
       end
 
+      describe '#worker' do
+        it 'returns a worker' do
+          expect(runner.worker).to respond_to :work_events
+        end
+
+        it 'setups the read callback to tell manager to handle pending events' do
+          expect(runner.manager).to receive :handle_pending_events
+          runner.worker.on_read.call
+        end
+
+        it 'setups the read_next callback to tell manager to handle next event' do
+          expect(runner.manager).to receive :handle_next_event
+          runner.worker.on_read_next.call
+        end
+
+        it 'setups the timeout callback to tell manager to flush the output' do
+          expect(runner.manager).to receive :flush
+          runner.worker.on_timeout.call
+        end
+      end
+
       describe '#run_until' do
-        it 'tells the manager to handle events until given block is true' do
+        it 'tells the worker to watch the manager' do
+          expect(runner.worker).to receive(:watch).with runner.manager
+          runner.run_until { true }
+        end
+
+        it 'tells the worker to work events until given block is true' do
           block = proc { }
           allow(block).to receive(:call).and_return(false, false, false, true)
-          expect(runner.manager).to receive(:handle_pending_events).exactly(3).times
+          expect(runner.worker).to receive(:work_events).exactly(3).times
           runner.run_until &block
         end
       end