diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f71699b60..38d44b84b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -28,6 +28,13 @@
     * Class methods (methods starting with a `@`)
     * Instance variables
     * Instance methods
+  * Be ware of platform differences
+    * The home directory is `process.env.USERPROFILE` on Windows, while on OS X
+      and Linux it's `process.env.HOME`
+    * Path separator is `\` on Windows, and is `/` on OS X and Linux, so use
+      `path.join` to concatenate filenames.
+    * Temporary directory is not `/tmp` on Windows, use `os.tmpdir()` when
+      possible
 
 ## Philosophy
 
diff --git a/Gruntfile.coffee b/Gruntfile.coffee
index 89e11a1dd..056c2aa3d 100644
--- a/Gruntfile.coffee
+++ b/Gruntfile.coffee
@@ -1,5 +1,6 @@
 fs = require 'fs'
 path = require 'path'
+os = require 'os'
 
 fm = require 'json-front-matter'
 _ = require 'underscore-plus'
@@ -9,7 +10,8 @@ packageJson = require './package.json'
 module.exports = (grunt) ->
   appName = 'Atom.app'
   [major, minor, patch] = packageJson.version.split('.')
-  buildDir = grunt.option('build-dir') ? '/tmp/atom-build'
+  tmpDir = if process.platform is 'win32' then os.tmpdir() else '/tmp'
+  buildDir = grunt.option('build-dir') ? path.join(tmpDir, 'atom-build')
   shellAppDir = path.join(buildDir, appName)
   contentsDir = path.join(shellAppDir, 'Contents')
   appDir = path.join(contentsDir, 'Resources', 'app')
diff --git a/spec/command-installer-spec.coffee b/spec/command-installer-spec.coffee
index 2734fb7f7..52bbb6ad5 100644
--- a/spec/command-installer-spec.coffee
+++ b/spec/command-installer-spec.coffee
@@ -1,10 +1,12 @@
 {fs} = require 'atom'
+path = require 'path'
+temp = require 'temp'
 installer = require '../src/command-installer'
 
 describe "install(commandPath, callback)", ->
-  directory = '/tmp/install-atom-command/atom'
-  commandPath = "#{directory}/source"
-  destinationPath = "#{directory}/bin/source"
+  directory = path.join(temp.dir, 'install-atom-command', 'atom')
+  commandPath = path.join(directory, 'source')
+  destinationPath = path.join(directory, 'bin', 'source')
 
   beforeEach ->
     spyOn(installer, 'findInstallDirectory').andCallFake (callback) ->
diff --git a/spec/config-spec.coffee b/spec/config-spec.coffee
index 7e60ba0d3..277a8a2d3 100644
--- a/spec/config-spec.coffee
+++ b/spec/config-spec.coffee
@@ -1,8 +1,11 @@
 {fs} = require 'atom'
 path = require 'path'
+temp = require 'temp'
 CSON = require 'season'
 
 describe "Config", ->
+  dotAtomPath = path.join(temp.dir, 'dot-atom-dir')
+
   describe ".get(keyPath)", ->
     it "allows a key path's value to be read", ->
       expect(config.set("foo.bar.baz", 42)).toBe 42
@@ -162,11 +165,11 @@ describe "Config", ->
 
   describe ".initializeConfigDirectory()", ->
     beforeEach ->
-      config.configDirPath = '/tmp/dot-atom-dir'
+      config.configDirPath = dotAtomPath
       expect(fs.exists(config.configDirPath)).toBeFalsy()
 
     afterEach ->
-      fs.remove('/tmp/dot-atom-dir') if fs.exists('/tmp/dot-atom-dir')
+      fs.remove(dotAtomPath) if fs.exists(dotAtomPath)
 
     describe "when the configDirPath doesn't exist", ->
       it "copies the contents of dot-atom to ~/.atom", ->
@@ -185,12 +188,12 @@ describe "Config", ->
 
   describe ".loadUserConfig()", ->
     beforeEach ->
-      config.configDirPath = '/tmp/dot-atom-dir'
+      config.configDirPath = dotAtomPath
       config.configFilePath = path.join(config.configDirPath, "config.cson")
       expect(fs.exists(config.configDirPath)).toBeFalsy()
 
     afterEach ->
-      fs.remove('/tmp/dot-atom-dir') if fs.exists('/tmp/dot-atom-dir')
+      fs.remove(dotAtomPath) if fs.exists(dotAtomPath)
 
     describe "when the config file contains valid cson", ->
       beforeEach ->
@@ -222,7 +225,7 @@ describe "Config", ->
     updatedHandler = null
 
     beforeEach ->
-      config.configDirPath = '/tmp/dot-atom-dir'
+      config.configDirPath = dotAtomPath
       config.configFilePath = path.join(config.configDirPath, "config.cson")
       expect(fs.exists(config.configDirPath)).toBeFalsy()
       fs.writeSync(config.configFilePath, "foo: bar: 'baz'")
@@ -233,7 +236,7 @@ describe "Config", ->
 
     afterEach ->
       config.unobserveUserConfig()
-      fs.remove('/tmp/dot-atom-dir') if fs.exists('/tmp/dot-atom-dir')
+      fs.remove(dotAtomPath) if fs.exists(dotAtomPath)
 
     describe "when the config file changes to contain valid cson", ->
       it "updates the config data", ->
diff --git a/spec/editor-spec.coffee b/spec/editor-spec.coffee
index c0c6dd6f8..595e025dd 100644
--- a/spec/editor-spec.coffee
+++ b/spec/editor-spec.coffee
@@ -1,5 +1,6 @@
 {_, $, $$, fs, Editor, Range, RootView} = require 'atom'
 path = require 'path'
+temp = require 'temp'
 
 describe "Editor", ->
   [buffer, editor, editSession, cachedLineHeight, cachedCharWidth] = []
@@ -86,7 +87,7 @@ describe "Editor", ->
 
   describe "when the activeEditSession's file is modified on disk", ->
     it "triggers an alert", ->
-      filePath = "/tmp/atom-changed-file.txt"
+      filePath = path.join(temp.dir, 'atom-changed-file.txt')
       fs.writeSync(filePath, "")
       editSession = project.openSync(filePath)
       editor.edit(editSession)
@@ -151,7 +152,7 @@ describe "Editor", ->
       expect(editor.lineElementForScreenRow(6).text()).toMatch /^      currentgoodbye/
 
     it "triggers alert if edit session's buffer goes into conflict with changes on disk", ->
-      filePath = "/tmp/atom-changed-file.txt"
+      filePath = path.join(temp.dir, 'atom-changed-file.txt')
       fs.writeSync(filePath, "")
       tempEditSession = project.openSync(filePath)
       editor.edit(tempEditSession)
@@ -247,7 +248,7 @@ describe "Editor", ->
     filePath = null
 
     beforeEach ->
-      filePath = "/tmp/something.txt"
+      filePath = path.join(temp.dir, 'something.txt')
       fs.writeSync(filePath, filePath)
 
     afterEach ->
@@ -274,11 +275,11 @@ describe "Editor", ->
       expect(eventHandler).toHaveBeenCalled()
 
       eventHandler.reset()
-      oldBuffer.saveAs("/tmp/atom-bad.txt")
+      oldBuffer.saveAs(path.join(temp.dir, 'atom-bad.txt'))
       expect(eventHandler).not.toHaveBeenCalled()
 
       eventHandler.reset()
-      editor.getBuffer().saveAs("/tmp/atom-new.txt")
+      editor.getBuffer().saveAs(path.join(temp.dir, 'atom-new.txt'))
       expect(eventHandler).toHaveBeenCalled()
 
     it "loads the grammar for the new path", ->
@@ -2296,7 +2297,8 @@ describe "Editor", ->
     [filePath] = []
 
     beforeEach ->
-      filePath = path.join(fs.absolute("/tmp"), "grammar-change.txt")
+      tmpdir = fs.absolute(temp.dir)
+      filePath = path.join(tmpdir, "grammar-change.txt")
       fs.writeSync(filePath, "var i;")
 
     afterEach ->
@@ -2648,10 +2650,11 @@ describe "Editor", ->
 
       editor.trigger 'editor:save-debug-snapshot'
 
+      statePath = path.join(temp.dir, 'state')
       expect(atom.showSaveDialog).toHaveBeenCalled()
-      saveDialogCallback('/tmp/state')
+      saveDialogCallback(statePath)
       expect(fs.writeSync).toHaveBeenCalled()
-      expect(fs.writeSync.argsForCall[0][0]).toBe '/tmp/state'
+      expect(fs.writeSync.argsForCall[0][0]).toBe statePath
       expect(typeof fs.writeSync.argsForCall[0][1]).toBe 'string'
 
   describe "when the escape key is pressed on the editor", ->
diff --git a/spec/fs-utils-spec.coffee b/spec/fs-utils-spec.coffee
index 755b6bbdf..c86d33512 100644
--- a/spec/fs-utils-spec.coffee
+++ b/spec/fs-utils-spec.coffee
@@ -33,12 +33,15 @@ describe "fs", ->
       expect(fs.exists(null)).toBe false
 
   describe ".makeTree(path)", ->
+    aPath = path.join(temp.dir, 'a')
+
     beforeEach ->
-      fs.remove("/tmp/a") if fs.exists("/tmp/a")
+      fs.remove(aPath) if fs.exists(aPath)
 
     it "creates all directories in path including any missing parent directories", ->
-      fs.makeTree("/tmp/a/b/c")
-      expect(fs.exists("/tmp/a/b/c")).toBeTruthy()
+      abcPath = path.join(aPath, 'b', 'c')
+      fs.makeTree(abcPath)
+      expect(fs.exists(abcPath)).toBeTruthy()
 
   describe ".traverseTreeSync(path, onFile, onDirectory)", ->
     it "calls fn for every path in the tree at the given path", ->
@@ -131,6 +134,7 @@ describe "fs", ->
 
   describe ".absolute(relativePath)", ->
     it "converts a leading ~ segment to the HOME directory", ->
-      expect(fs.absolute('~')).toBe fs.realpathSync(process.env.HOME)
-      expect(fs.absolute(path.join('~', 'does', 'not', 'exist'))).toBe path.join(process.env.HOME, 'does', 'not', 'exist')
+      homeDir = atom.getHomeDirPath()
+      expect(fs.absolute('~')).toBe fs.realpathSync(homeDir)
+      expect(fs.absolute(path.join('~', 'does', 'not', 'exist'))).toBe path.join(homeDir, 'does', 'not', 'exist')
       expect(fs.absolute('~test')).toBe '~test'
diff --git a/spec/git-spec.coffee b/spec/git-spec.coffee
index 170eccf2f..14725b4e0 100644
--- a/spec/git-spec.coffee
+++ b/spec/git-spec.coffee
@@ -8,18 +8,19 @@ describe "Git", ->
   repo = null
 
   beforeEach ->
-    fs.remove('/tmp/.git') if fs.isDirectorySync('/tmp/.git')
+    gitPath = path.join(temp.dir, '.git')
+    fs.remove(gitPath) if fs.isDirectorySync(gitPath)
 
   afterEach ->
     repo.destroy() if repo?.repo?
 
   describe "@open(path)", ->
     it "returns null when no repository is found", ->
-      expect(Git.open('/tmp/nogit.txt')).toBeNull()
+      expect(Git.open(path.join(temp.dir, 'nogit.txt'))).toBeNull()
 
   describe "new Git(path)", ->
     it "throws an exception when no repository is found", ->
-      expect(-> new Git('/tmp/nogit.txt')).toThrow()
+      expect(-> new Git(path.join(temp.dir, 'nogit.txt'))).toThrow()
 
   describe ".getPath()", ->
     it "returns the repository path for a .git directory path", ->
diff --git a/spec/pane-container-replication-spec.coffee b/spec/pane-container-replication-spec.coffee
index 0a61a87d0..b7ce80977 100644
--- a/spec/pane-container-replication-spec.coffee
+++ b/spec/pane-container-replication-spec.coffee
@@ -1,3 +1,5 @@
+path = require 'path'
+temp = require 'temp'
 {Site} = require 'telepath'
 {View} = require 'atom'
 PaneContainer = require '../src/pane-container'
@@ -13,7 +15,7 @@ describe "PaneContainer replication", ->
     initialize: (@name) -> @text(@name)
     serialize: -> { deserializer: 'TestView', @name }
     getState: -> @serialize()
-    getUri: -> "/tmp/#{@name}"
+    getUri: -> path.join(temp.dir, @name)
     isEqual: (other) -> @name is other.name
 
   beforeEach ->
diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index 4a773e6c7..a2210ad41 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -1,3 +1,5 @@
+path = require 'path'
+temp = require 'temp'
 PaneContainer = require '../src/pane-container'
 Pane = require '../src/pane'
 {_, $, View, $$} = require 'atom'
@@ -12,7 +14,7 @@ describe "PaneContainer", ->
       @content: -> @div tabindex: -1
       initialize: (@name) -> @text(@name)
       serialize: -> { deserializer: 'TestView', @name }
-      getUri: -> "/tmp/#{@name}"
+      getUri: -> path.join(temp.dir, @name)
       save: -> @saved = true
       isEqual: (other) -> @name is other.name
 
diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index 52a35b601..00d889718 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -1,7 +1,8 @@
 PaneContainer = require '../src/pane-container'
 Pane = require '../src/pane'
 {$, View} = require 'atom'
-{dirname} = require 'path'
+path = require 'path'
+temp = require 'temp'
 
 describe "Pane", ->
   [container, view1, view2, editSession1, editSession2, pane] = []
@@ -372,7 +373,7 @@ describe "Pane", ->
 
         pane.trigger 'core:save-as'
 
-        expect(atom.showSaveDialogSync).toHaveBeenCalledWith(dirname(editSession2.getPath()))
+        expect(atom.showSaveDialogSync).toHaveBeenCalledWith(path.dirname(editSession2.getPath()))
         expect(editSession2.saveAs).toHaveBeenCalledWith('/selected/path')
 
     describe "when the current item does not have a saveAs method", ->
@@ -679,7 +680,7 @@ describe "Pane", ->
         expect(pane.saveItem).not.toHaveBeenCalled()
         expect(pane.activeItem.save).not.toHaveBeenCalled()
 
-        initialActiveItemUri = '/tmp/hi'
+        initialActiveItemUri = path.join(temp.dir, 'hi')
         pane.activeView.trigger 'focusout'
         expect(pane.activeItem.save).toHaveBeenCalled()
 
@@ -697,7 +698,7 @@ describe "Pane", ->
         expect(initialActiveItem.save).not.toHaveBeenCalled()
 
         pane.showItem(initialActiveItem)
-        initialActiveItemUri = '/tmp/hi'
+        initialActiveItemUri = path.join(temp.dir, 'hi')
         pane.showItem(view2)
         expect(initialActiveItem.save).toHaveBeenCalled()
 
@@ -716,7 +717,7 @@ describe "Pane", ->
         pane.destroyItem(view2)
         expect(pane.saveItem).not.toHaveBeenCalled()
 
-        initialActiveItemUri = '/tmp/hi'
+        initialActiveItemUri = path.join(temp.dir, 'hi')
         pane.destroyItem(initialActiveItem)
         expect(initialActiveItem.save).toHaveBeenCalled()
 
diff --git a/spec/root-view-spec.coffee b/spec/root-view-spec.coffee
index 14280070e..76630c0ca 100644
--- a/spec/root-view-spec.coffee
+++ b/spec/root-view-spec.coffee
@@ -1,6 +1,7 @@
 {$, $$, fs, RootView, View} = require 'atom'
 Q = require 'q'
 path = require 'path'
+temp = require 'temp'
 Pane = require '../src/pane'
 
 describe "RootView", ->
@@ -162,7 +163,7 @@ describe "RootView", ->
       describe "when the title of the active pane item changes", ->
         it "updates the window title based on the item's new title", ->
           editSession = rootView.getActivePaneItem()
-          editSession.buffer.setPath('/tmp/hi')
+          editSession.buffer.setPath(path.join(temp.dir, 'hi'))
           expect(rootView.title).toBe "#{editSession.getTitle()} - #{project.getPath()}"
 
       describe "when the active pane's item changes", ->
diff --git a/spec/syntax-spec.coffee b/spec/syntax-spec.coffee
index f09087a37..b3e46ff38 100644
--- a/spec/syntax-spec.coffee
+++ b/spec/syntax-spec.coffee
@@ -1,4 +1,6 @@
 {fs} = require 'atom'
+path = require 'path'
+temp = require 'temp'
 TextMateGrammar = require '../src/text-mate-grammar'
 
 describe "the `syntax` global", ->
@@ -10,19 +12,19 @@ describe "the `syntax` global", ->
 
   describe "serialization", ->
     it "remembers grammar overrides by path", ->
-      path = '/foo/bar/file.js'
-      expect(syntax.selectGrammar(path).name).not.toBe 'Ruby'
-      syntax.setGrammarOverrideForPath(path, 'source.ruby')
+      filePath = '/foo/bar/file.js'
+      expect(syntax.selectGrammar(filePath).name).not.toBe 'Ruby'
+      syntax.setGrammarOverrideForPath(filePath, 'source.ruby')
       syntax2 = deserialize(syntax.serialize())
       syntax2.addGrammar(grammar) for grammar in syntax.grammars when grammar isnt syntax.nullGrammar
-      expect(syntax2.selectGrammar(path).name).toBe 'Ruby'
+      expect(syntax2.selectGrammar(filePath).name).toBe 'Ruby'
 
   describe ".selectGrammar(filePath)", ->
     it "can use the filePath to load the correct grammar based on the grammar's filetype", ->
       atom.activatePackage('git-tmbundle', sync: true)
 
       expect(syntax.selectGrammar("file.js").name).toBe "JavaScript" # based on extension (.js)
-      expect(syntax.selectGrammar("/tmp/.git/config").name).toBe "Git Config" # based on end of the path (.git/config)
+      expect(syntax.selectGrammar(path.join(temp.dir, '.git', 'config')).name).toBe "Git Config" # based on end of the path (.git/config)
       expect(syntax.selectGrammar("Rakefile").name).toBe "Ruby" # based on the file's basename (Rakefile)
       expect(syntax.selectGrammar("curb").name).toBe "Null Grammar"
       expect(syntax.selectGrammar("/hu.git/config").name).toBe "Null Grammar"
@@ -51,12 +53,12 @@ describe "the `syntax` global", ->
       expect(fs.read).not.toHaveBeenCalled()
 
     it "allows the default grammar to be overridden for a path", ->
-      path = '/foo/bar/file.js'
-      expect(syntax.selectGrammar(path).name).not.toBe 'Ruby'
-      syntax.setGrammarOverrideForPath(path, 'source.ruby')
-      expect(syntax.selectGrammar(path).name).toBe 'Ruby'
-      syntax.clearGrammarOverrideForPath(path)
-      expect(syntax.selectGrammar(path).name).not.toBe 'Ruby'
+      filePath = '/foo/bar/file.js'
+      expect(syntax.selectGrammar(filePath).name).not.toBe 'Ruby'
+      syntax.setGrammarOverrideForPath(filePath, 'source.ruby')
+      expect(syntax.selectGrammar(filePath).name).toBe 'Ruby'
+      syntax.clearGrammarOverrideForPath(filePath)
+      expect(syntax.selectGrammar(filePath).name).not.toBe 'Ruby'
 
     describe "when multiple grammars have matching fileTypes", ->
       it "selects the grammar with the longest fileType match", ->
diff --git a/spec/text-buffer-spec.coffee b/spec/text-buffer-spec.coffee
index 34e928b07..660309386 100644
--- a/spec/text-buffer-spec.coffee
+++ b/spec/text-buffer-spec.coffee
@@ -154,7 +154,7 @@ describe 'TextBuffer', ->
     [filePath, bufferToDelete] = []
 
     beforeEach ->
-      filePath = "/tmp/atom-file-to-delete.txt"
+      filePath = path.join(temp.dir, 'atom-file-to-delete.txt')
       fs.writeSync(filePath, 'delete me')
       bufferToDelete = project.bufferForPathSync(filePath)
       filePath = bufferToDelete.getPath() # symlinks may have been converted
@@ -212,7 +212,7 @@ describe 'TextBuffer', ->
 
     it "reports the modified status changing to true after the underlying file is deleted", ->
       buffer.release()
-      filePath = "/tmp/atom-tmp-file"
+      filePath = path.join(temp.dir, 'atom-tmp-file')
       fs.writeSync(filePath, 'delete me')
       buffer = project.bufferForPathSync(filePath)
       modifiedHandler = jasmine.createSpy("modifiedHandler")
@@ -224,7 +224,7 @@ describe 'TextBuffer', ->
       runs -> expect(buffer.isModified()).toBe true
 
     it "reports the modified status changing to false after a modified buffer is saved", ->
-      filePath = "/tmp/atom-tmp-file"
+      filePath = path.join(temp.dir, 'atom-tmp-file')
       fs.writeSync(filePath, '')
       buffer.release()
       buffer = project.bufferForPathSync(filePath)
@@ -248,7 +248,7 @@ describe 'TextBuffer', ->
       expect(buffer.isModified()).toBe true
 
     it "reports the modified status changing to false after a modified buffer is reloaded", ->
-      filePath = "/tmp/atom-tmp-file"
+      filePath = path.join(temp.dir, 'atom-tmp-file')
       fs.writeSync(filePath, '')
       buffer.release()
       buffer = project.bufferForPathSync(filePath)
@@ -271,7 +271,7 @@ describe 'TextBuffer', ->
       expect(buffer.isModified()).toBe true
 
     it "reports the modified status changing to false after a buffer to a non-existent file is saved", ->
-      filePath = "/tmp/atom-tmp-file"
+      filePath = path.join(temp.dir, 'atom-tmp-file')
       fs.remove(filePath) if fs.exists(filePath)
       expect(fs.exists(filePath)).toBeFalsy()
       buffer.release()
@@ -464,7 +464,7 @@ describe 'TextBuffer', ->
       filePath = null
 
       beforeEach ->
-        filePath = '/tmp/temp.txt'
+        filePath = path.join(temp.dir, 'temp.txt')
         fs.writeSync(filePath, "")
         saveBuffer = project.bufferForPathSync(filePath)
         saveBuffer.setText("blah")
@@ -521,7 +521,7 @@ describe 'TextBuffer', ->
       saveAsBuffer.release()
 
     it "saves the contents of the buffer to the path", ->
-      filePath = '/tmp/temp.txt'
+      filePath = path.join(temp.dir, 'temp.txt')
       fs.remove filePath if fs.exists(filePath)
 
       saveAsBuffer = project.bufferForPathSync(null).retain()
@@ -535,8 +535,8 @@ describe 'TextBuffer', ->
       expect(eventHandler).toHaveBeenCalledWith(saveAsBuffer)
 
     it "stops listening to events on previous path and begins listening to events on new path", ->
-      originalPath = "/tmp/original.txt"
-      newPath = "/tmp/new.txt"
+      originalPath = path.join(temp.dir, 'original.txt')
+      newPath = path.join(temp.dir, 'new.txt')
       fs.writeSync(originalPath, "")
 
       saveAsBuffer = project.bufferForPathSync(originalPath).retain()
diff --git a/src/atom.coffee b/src/atom.coffee
index 0b6d3896f..8aadbbe5b 100644
--- a/src/atom.coffee
+++ b/src/atom.coffee
@@ -13,6 +13,7 @@ remote = require 'remote'
 shell = require 'shell'
 crypto = require 'crypto'
 path = require 'path'
+os = require 'os'
 dialog = remote.require 'dialog'
 app = remote.require 'app'
 {Document} = require 'telepath'
@@ -229,7 +230,10 @@ class Atom
     @getCurrentWindow().isFullScreen()
 
   getHomeDirPath: ->
-    app.getHomeDir()
+    process.env[if process.platform is 'win32' then 'USERPROFILE' else 'HOME']
+
+  getTempDirPath: ->
+    if process.platform is 'win32' then os.tmpdir() else '/tmp'
 
   # Public: Get the directory path to Atom's configuration area.
   getConfigDirPath: ->
diff --git a/src/browser/atom-application.coffee b/src/browser/atom-application.coffee
index 995fede94..d0ec2441f 100644
--- a/src/browser/atom-application.coffee
+++ b/src/browser/atom-application.coffee
@@ -8,13 +8,14 @@ dialog = require 'dialog'
 fs = require 'fs'
 ipc = require 'ipc'
 path = require 'path'
+os = require 'os'
 net = require 'net'
 shell = require 'shell'
 url = require 'url'
 {EventEmitter} = require 'events'
 _ = require 'underscore-plus'
 
-socketPath = '/tmp/atom.sock'
+socketPath = path.join(os.tmpdir(), 'atom.sock')
 
 # Private: The application's singleton class.
 #
diff --git a/src/coffee-cache.coffee b/src/coffee-cache.coffee
index 25c6a7472..263cd924c 100644
--- a/src/coffee-cache.coffee
+++ b/src/coffee-cache.coffee
@@ -1,12 +1,14 @@
 crypto = require 'crypto'
 fs = require 'fs'
 path = require 'path'
+os = require 'os'
 
 CoffeeScript = require 'coffee-script'
 CSON = require 'season'
 mkdir = require('mkdirp').sync
 
-cacheDir = '/tmp/atom-compile-cache'
+tmpDir = if process.platform is 'win32' then os.tmpdir() else '/tmp'
+cacheDir = path.join(tmpDir, 'atom-compile-cache')
 coffeeCacheDir = path.join(cacheDir, 'coffee')
 CSON.setCacheDir(path.join(cacheDir, 'cson'))
 
diff --git a/src/fs-utils.coffee b/src/fs-utils.coffee
index 94a3b4b5d..19e16d7db 100644
--- a/src/fs-utils.coffee
+++ b/src/fs-utils.coffee
@@ -13,10 +13,12 @@ fsExtensions =
   absolute: (relativePath) ->
     return null unless relativePath?
 
+    homeDir = process.env[if process.platform is 'win32' then 'USERPROFILE' else 'HOME']
+
     if relativePath is '~'
-      relativePath = process.env.HOME
+      relativePath = homeDir
     else if relativePath.indexOf('~/') is 0
-      relativePath = "#{process.env.HOME}#{relativePath.substring(1)}"
+      relativePath = "#{homeDir}#{relativePath.substring(1)}"
 
     try
       fs.realpathSync(relativePath)
diff --git a/src/less-compile-cache.coffee b/src/less-compile-cache.coffee
index 8dfafa27e..977ede9ff 100644
--- a/src/less-compile-cache.coffee
+++ b/src/less-compile-cache.coffee
@@ -1,12 +1,15 @@
 path = require 'path'
+os = require 'os'
 LessCache = require 'less-cache'
 {Subscriber} = require 'emissary'
 
+tmpDir = if process.platform is 'win32' then os.tmpdir() else '/tmp'
+
 module.exports =
 class LessCompileCache
   Subscriber.includeInto(this)
 
-  @cacheDir: '/tmp/atom-compile-cache/less'
+  @cacheDir: path.join(tmpDir, 'atom-compile-cache', 'less')
 
   constructor: ->
     @cache = new LessCache
diff --git a/tasks/clean-task.coffee b/tasks/clean-task.coffee
index 23b6da973..1d0befa3f 100644
--- a/tasks/clean-task.coffee
+++ b/tasks/clean-task.coffee
@@ -1,16 +1,21 @@
 path = require 'path'
+os = require 'os'
 
 module.exports = (grunt) ->
   {rm} = require('./task-helpers')(grunt)
 
   grunt.registerTask 'partial-clean', 'Delete some of the build files', ->
+    tmpdir = if process.platform is 'win32' then os.tmpdir() else '/tmp'
+
     rm grunt.config.get('atom.buildDir')
     rm require('../src/coffee-cache').cacheDir
     rm require('../src/less-compile-cache').cacheDir
-    rm '/tmp/atom-cached-atom-shells'
+    rm path.join(tmpdir, 'atom-cached-atom-shells')
     rm 'atom-shell'
 
   grunt.registerTask 'clean', 'Delete all the build files', ->
+    homeDir = process.env[if process.platform is 'win32' then 'USERPROFILE' else 'HOME']
+
     rm 'node_modules'
-    rm path.join(process.env.HOME, '.atom', '.node-gyp')
+    rm path.join(homeDir, '.atom', '.node-gyp')
     grunt.task.run('partial-clean')
diff --git a/tasks/update-atom-shell-task.coffee b/tasks/update-atom-shell-task.coffee
index 9cbd0ea99..f42cef571 100644
--- a/tasks/update-atom-shell-task.coffee
+++ b/tasks/update-atom-shell-task.coffee
@@ -1,5 +1,6 @@
 fs = require 'fs'
 path = require 'path'
+os = require 'os'
 
 request = require 'request'
 formidable = require 'formidable'
@@ -70,7 +71,11 @@ module.exports = (grunt) ->
     else
       null
 
-  getCachePath = (version) -> "/tmp/atom-cached-atom-shells/#{version}"
+  getTempDir = ->
+    if process.platform is 'win32' then os.tmpdir() else '/tmp'
+
+  getCachePath = (version) ->
+    path.join(getTempDir(), 'atom-cached-atom-shells', version)
 
   isAtomShellVersionCached = (version) ->
     grunt.file.isFile(getCachePath(version), 'version')