diff --git a/.coveragerc b/.coveragerc
index 7c462b3c..c6d704c6 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -14,6 +14,8 @@ omit =
 exclude_lines =
     # Have to re-enable the standard pragma
     \#\s*pragma: no cover
+    # We optionally substitute this
+    ${COVERAGE_IGNORE_WINDOWS}
 
     # Don't complain if tests don't hit defensive assertion code:
     ^\s*raise AssertionError\b
diff --git a/.travis.yml b/.travis.yml
index a01003c3..55f7c310 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,9 @@
 language: python
 python: 3.5
+dist: trusty
+sudo: required
+services:
+    - docker
 env: # These should match the tox env list
     - TOXENV=py27
     - TOXENV=py34
@@ -18,11 +22,11 @@ before_install:
             export PATH="/tmp/git/bin:$PATH"
         fi
     - git --version
+    - |
+        ./get-swift.sh
+        export PATH="/tmp/swift/usr/bin:$PATH"
 after_success:
     - coveralls
-sudo: required
-services:
-    - docker
 cache:
     directories:
         - $HOME/.cache/pip
diff --git a/appveyor.yml b/appveyor.yml
index d59a852f..c02598dc 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,4 +1,7 @@
 environment:
+    global:
+        COVERAGE_IGNORE_WINDOWS: '# pragma: windows no cover'
+        TOX_TESTENV_PASSENV: COVERAGE_IGNORE_WINDOWS
     matrix:
         - TOXENV: py27
         - TOXENV: py35
diff --git a/get-swift.sh b/get-swift.sh
new file mode 100755
index 00000000..e5cc570b
--- /dev/null
+++ b/get-swift.sh
@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+# This is a script used in travis-ci to install swift
+set -ex
+
+. /etc/lsb-release
+if [ "$DISTRIB_CODENAME" = "trusty" ]; then
+    SWIFT_URL='https://swift.org/builds/swift-3.0.2-release/ubuntu1404/swift-3.0.2-RELEASE/swift-3.0.2-RELEASE-ubuntu14.04.tar.gz'
+else
+    SWIFT_URL='https://swift.org/builds/swift-3.0.2-release/ubuntu1604/swift-3.0.2-RELEASE/swift-3.0.2-RELEASE-ubuntu16.04.tar.gz'
+fi
+
+mkdir -p /tmp/swift
+pushd /tmp/swift
+    wget "$SWIFT_URL" -O swift.tar.gz
+    tar -xf swift.tar.gz --strip 1
+popd
diff --git a/pre_commit/languages/all.py b/pre_commit/languages/all.py
index a517ee85..cc7af88c 100644
--- a/pre_commit/languages/all.py
+++ b/pre_commit/languages/all.py
@@ -6,6 +6,7 @@ from pre_commit.languages import pcre
 from pre_commit.languages import python
 from pre_commit.languages import ruby
 from pre_commit.languages import script
+from pre_commit.languages import swift
 from pre_commit.languages import system
 
 # A language implements the following constant and two functions in its module:
@@ -47,6 +48,7 @@ languages = {
     'python': python,
     'ruby': ruby,
     'script': script,
+    'swift': swift,
     'system': system,
 }
 
diff --git a/pre_commit/languages/docker.py b/pre_commit/languages/docker.py
index cfd38ddb..2e9129a7 100644
--- a/pre_commit/languages/docker.py
+++ b/pre_commit/languages/docker.py
@@ -16,30 +16,30 @@ ENVIRONMENT_DIR = 'docker'
 PRE_COMMIT_LABEL = 'PRE_COMMIT'
 
 
-def md5(s):
+def md5(s):  # pragma: windows no cover
     return hashlib.md5(five.to_bytes(s)).hexdigest()
 
 
-def docker_tag(repo_cmd_runner):
+def docker_tag(repo_cmd_runner):  # pragma: windows no cover
     return 'pre-commit-{}'.format(
         md5(os.path.basename(repo_cmd_runner.path()))
     ).lower()
 
 
-def docker_is_running():
+def docker_is_running():  # pragma: windows no cover
     try:
         return cmd_output('docker', 'ps')[0] == 0
     except CalledProcessError:
         return False
 
 
-def assert_docker_available():
+def assert_docker_available():  # pragma: windows no cover
     assert docker_is_running(), (
         'Docker is either not running or not configured in this environment'
     )
 
 
-def build_docker_image(repo_cmd_runner, **kwargs):
+def build_docker_image(repo_cmd_runner, **kwargs):  # pragma: windows no cover
     pull = kwargs.pop('pull')
     assert not kwargs, kwargs
     cmd = (
@@ -56,7 +56,7 @@ def install_environment(
         repo_cmd_runner,
         version='default',
         additional_dependencies=(),
-):
+):  # pragma: windows no cover
     assert repo_cmd_runner.exists('Dockerfile'), (
         'No Dockerfile was found in the hook repository'
     )
@@ -65,9 +65,9 @@ def install_environment(
     )
     assert_docker_available()
 
-    directory = repo_cmd_runner.path(helpers.environment_dir(
-        ENVIRONMENT_DIR, 'default',
-    ))
+    directory = repo_cmd_runner.path(
+        helpers.environment_dir(ENVIRONMENT_DIR, 'default'),
+    )
 
     # Docker doesn't really have relevant disk environment, but pre-commit
     # still needs to cleanup it's state files on failure
@@ -76,7 +76,7 @@ def install_environment(
         os.mkdir(directory)
 
 
-def run_hook(repo_cmd_runner, hook, file_args):
+def run_hook(repo_cmd_runner, hook, file_args):  # pragma: windows no cover
     assert_docker_available()
     # Rebuild the docker image in case it has gone missing, as many people do
     # automated cleanup of docker images.
diff --git a/pre_commit/languages/node.py b/pre_commit/languages/node.py
index a5919824..ef557a16 100644
--- a/pre_commit/languages/node.py
+++ b/pre_commit/languages/node.py
@@ -14,7 +14,7 @@ from pre_commit.xargs import xargs
 ENVIRONMENT_DIR = 'node_env'
 
 
-def get_env_patch(venv):
+def get_env_patch(venv):  # pragma: windows no cover
     return (
         ('NODE_VIRTUAL_ENV', venv),
         ('NPM_CONFIG_PREFIX', venv),
@@ -25,9 +25,8 @@ def get_env_patch(venv):
 
 
 @contextlib.contextmanager
-def in_env(repo_cmd_runner, language_version):
-    envdir = os.path.join(
-        repo_cmd_runner.prefix_dir,
+def in_env(repo_cmd_runner, language_version):  # pragma: windows no cover
+    envdir = repo_cmd_runner.path(
         helpers.environment_dir(ENVIRONMENT_DIR, language_version),
     )
     with envcontext(get_env_patch(envdir)):
@@ -38,7 +37,7 @@ def install_environment(
         repo_cmd_runner,
         version='default',
         additional_dependencies=(),
-):
+):  # pragma: windows no cover
     additional_dependencies = tuple(additional_dependencies)
     assert repo_cmd_runner.exists('package.json')
     directory = helpers.environment_dir(ENVIRONMENT_DIR, version)
@@ -62,6 +61,6 @@ def install_environment(
             )
 
 
-def run_hook(repo_cmd_runner, hook, file_args):
+def run_hook(repo_cmd_runner, hook, file_args):  # pragma: windows no cover
     with in_env(repo_cmd_runner, hook['language_version']):
         return xargs(helpers.to_cmd(hook), file_args)
diff --git a/pre_commit/languages/python.py b/pre_commit/languages/python.py
index 11be01d0..1e60a3ed 100644
--- a/pre_commit/languages/python.py
+++ b/pre_commit/languages/python.py
@@ -32,8 +32,7 @@ def get_env_patch(venv):
 
 @contextlib.contextmanager
 def in_env(repo_cmd_runner, language_version):
-    envdir = os.path.join(
-        repo_cmd_runner.prefix_dir,
+    envdir = repo_cmd_runner.path(
         helpers.environment_dir(ENVIRONMENT_DIR, language_version),
     )
     with envcontext(get_env_patch(envdir)):
diff --git a/pre_commit/languages/ruby.py b/pre_commit/languages/ruby.py
index 2e01012a..32682f52 100644
--- a/pre_commit/languages/ruby.py
+++ b/pre_commit/languages/ruby.py
@@ -18,7 +18,7 @@ from pre_commit.xargs import xargs
 ENVIRONMENT_DIR = 'rbenv'
 
 
-def get_env_patch(venv, language_version):
+def get_env_patch(venv, language_version):  # pragma: windows no cover
     patches = (
         ('GEM_HOME', os.path.join(venv, 'gems')),
         ('RBENV_ROOT', venv),
@@ -34,16 +34,17 @@ def get_env_patch(venv, language_version):
 
 
 @contextlib.contextmanager
-def in_env(repo_cmd_runner, language_version):
-    envdir = os.path.join(
-        repo_cmd_runner.prefix_dir,
+def in_env(repo_cmd_runner, language_version):  # pragma: windows no cover
+    envdir = repo_cmd_runner.path(
         helpers.environment_dir(ENVIRONMENT_DIR, language_version),
     )
     with envcontext(get_env_patch(envdir, language_version)):
         yield
 
 
-def _install_rbenv(repo_cmd_runner, version='default'):
+def _install_rbenv(
+        repo_cmd_runner, version='default',
+):  # pragma: windows no cover
     directory = helpers.environment_dir(ENVIRONMENT_DIR, version)
 
     with tarfile.open(resource_filename('rbenv.tar.gz')) as tf:
@@ -86,7 +87,7 @@ def _install_rbenv(repo_cmd_runner, version='default'):
             activate_file.write('export RBENV_VERSION="{}"\n'.format(version))
 
 
-def _install_ruby(runner, version):
+def _install_ruby(runner, version):  # pragma: windows no cover
     try:
         helpers.run_setup_cmd(runner, ('rbenv', 'download', version))
     except CalledProcessError:  # pragma: no cover (usually find with download)
@@ -98,7 +99,7 @@ def install_environment(
         repo_cmd_runner,
         version='default',
         additional_dependencies=(),
-):
+):  # pragma: windows no cover
     additional_dependencies = tuple(additional_dependencies)
     directory = helpers.environment_dir(ENVIRONMENT_DIR, version)
     with clean_path_on_failure(repo_cmd_runner.path(directory)):
@@ -126,6 +127,6 @@ def install_environment(
             )
 
 
-def run_hook(repo_cmd_runner, hook, file_args):
+def run_hook(repo_cmd_runner, hook, file_args):  # pragma: windows no cover
     with in_env(repo_cmd_runner, hook['language_version']):
         return xargs(helpers.to_cmd(hook), file_args)
diff --git a/pre_commit/languages/swift.py b/pre_commit/languages/swift.py
new file mode 100644
index 00000000..d362e01e
--- /dev/null
+++ b/pre_commit/languages/swift.py
@@ -0,0 +1,56 @@
+from __future__ import unicode_literals
+
+import contextlib
+import os
+
+from pre_commit.envcontext import envcontext
+from pre_commit.envcontext import Var
+from pre_commit.languages import helpers
+from pre_commit.util import clean_path_on_failure
+from pre_commit.xargs import xargs
+
+ENVIRONMENT_DIR = 'swift_env'
+BUILD_DIR = '.build'
+BUILD_CONFIG = 'release'
+
+
+def get_env_patch(venv):  # pragma: windows no cover
+    bin_path = os.path.join(venv, BUILD_DIR, BUILD_CONFIG)
+    return (('PATH', (bin_path, os.pathsep, Var('PATH'))),)
+
+
+@contextlib.contextmanager
+def in_env(repo_cmd_runner):  # pragma: windows no cover
+    envdir = repo_cmd_runner.path(
+        helpers.environment_dir(ENVIRONMENT_DIR, 'default'),
+    )
+    with envcontext(get_env_patch(envdir)):
+        yield
+
+
+def install_environment(
+        repo_cmd_runner,
+        version='default',
+        additional_dependencies=(),
+):  # pragma: windows no cover
+    assert version == 'default', (
+        'Pre-commit does not support language_version for docker '
+    )
+    directory = repo_cmd_runner.path(
+        helpers.environment_dir(ENVIRONMENT_DIR, 'default'),
+    )
+
+    # Build the swift package
+    with clean_path_on_failure(directory):
+        os.mkdir(directory)
+        repo_cmd_runner.run((
+            'swift', 'build',
+            '-C', '{prefix}',
+            '-c', BUILD_CONFIG,
+            '--build-path', os.path.join(directory, BUILD_DIR),
+        ))
+
+
+def run_hook(repo_cmd_runner, hook, file_args):  # pragma: windows no cover
+    with in_env(repo_cmd_runner):
+        return xargs(helpers.to_cmd(hook), file_args)
diff --git a/testing/resources/swift_hooks_repo/.gitignore b/testing/resources/swift_hooks_repo/.gitignore
new file mode 100644
index 00000000..02c08753
--- /dev/null
+++ b/testing/resources/swift_hooks_repo/.gitignore
@@ -0,0 +1,4 @@
+.DS_Store
+/.build
+/Packages
+/*.xcodeproj
diff --git a/testing/resources/swift_hooks_repo/Package.swift b/testing/resources/swift_hooks_repo/Package.swift
new file mode 100644
index 00000000..6e02c188
--- /dev/null
+++ b/testing/resources/swift_hooks_repo/Package.swift
@@ -0,0 +1,5 @@
+import PackageDescription
+
+let package = Package(
+    name: "swift_hooks_repo"
+)
diff --git a/testing/resources/swift_hooks_repo/Sources/main.swift b/testing/resources/swift_hooks_repo/Sources/main.swift
new file mode 100644
index 00000000..f7cf60e1
--- /dev/null
+++ b/testing/resources/swift_hooks_repo/Sources/main.swift
@@ -0,0 +1 @@
+print("Hello, world!")
diff --git a/testing/resources/swift_hooks_repo/hooks.yaml b/testing/resources/swift_hooks_repo/hooks.yaml
new file mode 100644
index 00000000..c08df87d
--- /dev/null
+++ b/testing/resources/swift_hooks_repo/hooks.yaml
@@ -0,0 +1,6 @@
+-   id: swift-hooks-repo
+    name: Swift hooks repo example
+    description: Runs the hello world app generated by swift package init --type executable (binary called swift_hooks_repo here)
+    entry: swift_hooks_repo
+    language: swift
+    files: \.(swift)$
diff --git a/testing/util.py b/testing/util.py
index cf9dde9d..8fdf5777 100644
--- a/testing/util.py
+++ b/testing/util.py
@@ -6,6 +6,7 @@ import shutil
 import jsonschema
 import pytest
 
+from pre_commit import parse_shebang
 from pre_commit.languages.docker import docker_is_running
 from pre_commit.util import cmd_output
 from pre_commit.util import cwd
@@ -68,6 +69,11 @@ skipif_slowtests_false = pytest.mark.skipif(
     reason='slowtests=false',
 )
 
+skipif_cant_run_swift = pytest.mark.skipif(
+    parse_shebang.find_executable('swift') is None,
+    reason='swift isn\'t installed or can\'t be found'
+)
+
 xfailif_windows_no_ruby = pytest.mark.xfail(
     os.name == 'nt',
     reason='Ruby support not yet implemented on windows.',
diff --git a/tests/repository_test.py b/tests/repository_test.py
index ad3c8234..e37b304d 100644
--- a/tests/repository_test.py
+++ b/tests/repository_test.py
@@ -30,6 +30,7 @@ from testing.fixtures import make_config_from_repo
 from testing.fixtures import make_repo
 from testing.fixtures import modify_manifest
 from testing.util import skipif_cant_run_docker
+from testing.util import skipif_cant_run_swift
 from testing.util import skipif_slowtests_false
 from testing.util import xfailif_no_pcre_support
 from testing.util import xfailif_windows_no_node
@@ -214,6 +215,15 @@ def test_system_hook_with_spaces(tempdir_factory, store):
     )
 
 
+@skipif_cant_run_swift
+@pytest.mark.integration
+def test_swift_hook(tempdir_factory, store):
+    _test_hook_repo(
+        tempdir_factory, store, 'swift_hooks_repo',
+        'swift-hooks-repo', [], b'Hello, world!\n',
+    )
+
+
 @pytest.mark.integration
 def test_missing_executable(tempdir_factory, store):
     _test_hook_repo(