diff --git a/spec/extensions/editor-command-spec.coffee b/spec/extensions/editor-command-spec.coffee
new file mode 100644
index 000000000..9b1b9cf03
--- /dev/null
+++ b/spec/extensions/editor-command-spec.coffee
@@ -0,0 +1,150 @@
+EditorCommand = require 'editor-command'
+LowerCaseCommand = require 'lowercase-command'
+UpperCaseCommand = require 'uppercase-command'
+RootView = require 'root-view'
+fs = require 'fs'
+
+describe "EditorCommand", ->
+  [rootView, editor, path] = []
+
+  beforeEach ->
+    rootView = new RootView
+    rootView.open(require.resolve 'fixtures/sample.js')
+
+    rootView.focus()
+    editor = rootView.getActiveEditor()
+
+  afterEach ->
+    rootView.remove()
+
+  describe "@alterSelection()", ->
+    it "returns true when transformed text is non-empty", ->
+      transformed = false
+      altered = false
+      class CustomCommand extends EditorCommand
+        @getKeymaps: (editor) ->
+          'meta-V': 'custom'
+
+        @execute: (editor, event) ->
+          altered = @alterSelection editor, (text) ->
+            transformed = true
+            'new'
+
+      CustomCommand.activate(rootView)
+      editor.moveCursorToTop()
+      editor.selectToEndOfLine()
+      editor.trigger 'custom'
+      expect(transformed).toBe true
+      expect(altered).toBe true
+
+    it "returns false when transformed text is null", ->
+      transformed = false
+      altered = false
+      class CustomCommand extends EditorCommand
+        @getKeymaps: (editor) ->
+          'meta-V': 'custom'
+
+        @execute: (editor, event) ->
+          altered = @alterSelection editor, (text) ->
+            transformed = true
+            null
+
+      CustomCommand.activate(rootView)
+      editor.moveCursorToTop()
+      editor.selectToEndOfLine()
+      editor.trigger 'custom'
+      expect(transformed).toBe true
+      expect(altered).toBe false
+
+    it "returns false when transformed text is undefined", ->
+      transformed = false
+      altered = false
+      class CustomCommand extends EditorCommand
+        @getKeymaps: (editor) ->
+          'meta-V': 'custom'
+
+        @execute: (editor, event) ->
+          altered = @alterSelection editor, (text) ->
+            transformed = true
+            undefined
+
+      CustomCommand.activate(rootView)
+      editor.moveCursorToTop()
+      editor.selectToEndOfLine()
+      editor.trigger 'custom'
+      expect(transformed).toBe true
+      expect(altered).toBe false
+
+  describe "custom sub-class", ->
+    it "removes vowels from selected text", ->
+      class VowelRemover extends EditorCommand
+        @getKeymaps: (editor) ->
+          'meta-V': 'devowel'
+
+        @execute: (editor, event) ->
+          @alterSelection editor, (text) ->
+            text.replace(/[aeiouy]/gi, '')
+
+      VowelRemover.activate(rootView)
+      editor.moveCursorToTop()
+      editor.selectToEndOfLine()
+      editor.trigger 'devowel'
+      expect(editor.lineForBufferRow(0)).toBe 'vr qcksrt = fnctn () {'
+      expect(editor.getTextInRange(editor.getSelection().getBufferRange())).toBe 'vr qcksrt = fnctn () {'
+
+    it "doesn't transform empty selections", ->
+       callbackCount = 0
+       class CustomCommand extends EditorCommand
+         @getKeymaps: (editor) ->
+           'meta-V': 'custom'
+
+         @execute: (editor, event) ->
+           @alterSelection editor, (text) ->
+             callbackCount++
+             text
+
+       CustomCommand.activate(rootView)
+       editor.moveCursorToTop()
+       editor.selectToEndOfLine()
+       editor.trigger 'custom'
+       expect(callbackCount).toBe 1
+       editor.clearSelections()
+       editor.trigger 'custom'
+       expect(callbackCount).toBe 1
+
+    it "registers all keymaps", ->
+      callbackCount = 0
+      class CustomCommand extends EditorCommand
+        @getKeymaps: (editor) ->
+          'meta-V': 'custom1'
+          'meta-B': 'custom2'
+
+        @execute: (editor, event) ->
+          @alterSelection editor, (text) ->
+            callbackCount++
+            text
+
+        CustomCommand.activate(rootView)
+        editor.moveCursorToTop()
+        editor.selectToEndOfLine()
+        editor.trigger 'custom1'
+        expect(callbackCount).toBe 1
+        editor.trigger 'custom2'
+        expect(callbackCount).toBe 2
+
+  describe "LowerCaseCommand", ->
+    it "replaces the selected text with all lower case characters", ->
+      LowerCaseCommand.activate(rootView)
+      editor.setSelectedBufferRange([[11,14], [11,19]])
+      expect(editor.getTextInRange(editor.getSelection().getBufferRange())).toBe 'Array'
+      editor.trigger 'lowercase'
+      expect(editor.getTextInRange(editor.getSelection().getBufferRange())).toBe 'array'
+
+
+  describe "UpperCaseCommand", ->
+    it "replaces the selected text with all upper case characters", ->
+      UpperCaseCommand.activate(rootView)
+      editor.setSelectedBufferRange([[0,0], [0,3]])
+      expect(editor.getTextInRange(editor.getSelection().getBufferRange())).toBe 'var'
+      editor.trigger 'uppercase'
+      expect(editor.getTextInRange(editor.getSelection().getBufferRange())).toBe 'VAR'
diff --git a/src/extensions/editor-command.coffee b/src/extensions/editor-command.coffee
new file mode 100644
index 000000000..100c9ded7
--- /dev/null
+++ b/src/extensions/editor-command.coffee
@@ -0,0 +1,33 @@
+module.exports =
+class EditorCommand
+
+  @activate: (rootView) ->
+    keymaps = @getKeymaps()
+    return unless keymaps
+
+    window.keymap.bindKeys '.editor', keymaps
+
+    for editor in rootView.getEditors()
+      @subscribeToEditor(rootView, editor)
+
+    rootView.on 'editor-open', (e, editor) =>
+      @subscribeToEditor(rootView, editor)
+
+  @subscribeToEditor: (rootView, editor) ->
+    keymaps = @getKeymaps(rootView, editor)
+    return unless keymaps
+
+    for key, event of keymaps
+      editor.on event, => @execute(editor, event)
+
+  @alterSelection: (editor, transform) ->
+     selection = editor.getSelection()
+     return false if selection.isEmpty()
+
+     range = selection.getBufferRange()
+     reverse = selection.isReversed()
+     text = transform(editor.getTextInRange(range))
+     return false if text is null or text is undefined
+     editor.insertText(text)
+     selection.setBufferRange(range, {reverse})
+     true
diff --git a/src/extensions/lowercase-command.coffee b/src/extensions/lowercase-command.coffee
new file mode 100644
index 000000000..57ac1242d
--- /dev/null
+++ b/src/extensions/lowercase-command.coffee
@@ -0,0 +1,11 @@
+EditorCommand = require 'editor-command'
+
+module.exports =
+class LowerCaseCommand extends EditorCommand
+
+  @getKeymaps: (editor) ->
+    'meta-Y': 'lowercase'
+
+  @execute: (editor, event) ->
+    @alterSelection editor, (text) ->
+      text.toLowerCase()
diff --git a/src/extensions/uppercase-command.coffee b/src/extensions/uppercase-command.coffee
new file mode 100644
index 000000000..5a63f87e8
--- /dev/null
+++ b/src/extensions/uppercase-command.coffee
@@ -0,0 +1,11 @@
+EditorCommand = require 'editor-command'
+
+module.exports =
+class UpperCaseCommand extends EditorCommand
+
+  @getKeymaps: (editor) ->
+    'meta-X': 'uppercase'
+
+  @execute: (editor, event) ->
+    @alterSelection editor, (text) ->
+      text.toUpperCase()