Move the extensions resource to common/.
diff --git a/openstack/common/README.md b/openstack/common/README.md
new file mode 100644
index 0000000..7b55795
--- /dev/null
+++ b/openstack/common/README.md
@@ -0,0 +1,3 @@
+# Common Resources
+
+This directory is for resources that are shared by multiple services.
diff --git a/openstack/common/extensions/doc.go b/openstack/common/extensions/doc.go
new file mode 100644
index 0000000..4a168f4
--- /dev/null
+++ b/openstack/common/extensions/doc.go
@@ -0,0 +1,15 @@
+// Package extensions provides information and interaction with the different extensions available
+// for an OpenStack service.
+//
+// The purpose of OpenStack API extensions is to:
+//
+// - Introduce new features in the API without requiring a version change.
+// - Introduce vendor-specific niche functionality.
+// - Act as a proving ground for experimental functionalities that might be included in a future
+//   version of the API.
+//
+// Extensions usually have tags that prevent conflicts with other extensions that define attributes
+// or resources with the same names, and with core resources and attributes.
+// Because an extension might not be supported by all plug-ins, its availability varies with deployments
+// and the specific plug-in.
+package extensions
diff --git a/openstack/common/extensions/errors.go b/openstack/common/extensions/errors.go
new file mode 100644
index 0000000..aeec0fa
--- /dev/null
+++ b/openstack/common/extensions/errors.go
@@ -0,0 +1 @@
+package extensions
diff --git a/openstack/common/extensions/requests.go b/openstack/common/extensions/requests.go
new file mode 100644
index 0000000..8f7fd67
--- /dev/null
+++ b/openstack/common/extensions/requests.go
@@ -0,0 +1,27 @@
+package extensions
+
+import (
+	"github.com/racker/perigee"
+	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/pagination"
+)
+
+// Get retrieves information for a specific extension using its alias.
+func Get(c *gophercloud.ServiceClient, alias string) GetResult {
+	var res GetResult
+	_, err := perigee.Request("GET", extensionURL(c, alias), perigee.Options{
+		MoreHeaders: c.Provider.AuthenticatedHeaders(),
+		Results:     &res.Resp,
+		OkCodes:     []int{200},
+	})
+	res.Err = err
+	return res
+}
+
+// List returns a Pager which allows you to iterate over the full collection of
+// extensions. It does not accept query parameters.
+func List(c *gophercloud.ServiceClient) pagination.Pager {
+	return pagination.NewPager(c, listExtensionURL(c), func(r pagination.LastHTTPResponse) pagination.Page {
+		return ExtensionPage{pagination.SinglePageBase(r)}
+	})
+}
diff --git a/openstack/common/extensions/requests_test.go b/openstack/common/extensions/requests_test.go
new file mode 100644
index 0000000..5741280
--- /dev/null
+++ b/openstack/common/extensions/requests_test.go
@@ -0,0 +1,113 @@
+package extensions
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/pagination"
+	th "github.com/rackspace/gophercloud/testhelper"
+)
+
+const TokenID = "123"
+
+func ServiceClient() *gophercloud.ServiceClient {
+	return &gophercloud.ServiceClient{
+		Provider: &gophercloud.ProviderClient{
+			TokenID: TokenID,
+		},
+		Endpoint: th.Endpoint(),
+	}
+}
+
+func TestList(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+
+	th.Mux.HandleFunc("/v2.0/extensions", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "GET")
+		th.TestHeader(t, r, "X-Auth-Token", TokenID)
+
+		w.Header().Add("Content-Type", "application/json")
+
+		fmt.Fprintf(w, `
+{
+    "extensions": [
+        {
+            "updated": "2013-01-20T00:00:00-00:00",
+            "name": "Neutron Service Type Management",
+            "links": [],
+            "namespace": "http://docs.openstack.org/ext/neutron/service-type/api/v1.0",
+            "alias": "service-type",
+            "description": "API for retrieving service providers for Neutron advanced services"
+        }
+    ]
+}
+			`)
+	})
+
+	count := 0
+
+	List(ServiceClient()).EachPage(func(page pagination.Page) (bool, error) {
+		count++
+		actual, err := ExtractExtensions(page)
+		if err != nil {
+			t.Errorf("Failed to extract extensions: %v", err)
+		}
+
+		expected := []Extension{
+			Extension{
+				Updated:     "2013-01-20T00:00:00-00:00",
+				Name:        "Neutron Service Type Management",
+				Links:       []interface{}{},
+				Namespace:   "http://docs.openstack.org/ext/neutron/service-type/api/v1.0",
+				Alias:       "service-type",
+				Description: "API for retrieving service providers for Neutron advanced services",
+			},
+		}
+
+		th.AssertDeepEquals(t, expected, actual)
+
+		return true, nil
+	})
+
+	if count != 1 {
+		t.Errorf("Expected 1 page, got %d", count)
+	}
+}
+
+func TestGet(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+
+	th.Mux.HandleFunc("/v2.0/extensions/agent", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "GET")
+		th.TestHeader(t, r, "X-Auth-Token", TokenID)
+
+		w.Header().Add("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+
+		fmt.Fprintf(w, `
+{
+    "extension": {
+        "updated": "2013-02-03T10:00:00-00:00",
+        "name": "agent",
+        "links": [],
+        "namespace": "http://docs.openstack.org/ext/agent/api/v2.0",
+        "alias": "agent",
+        "description": "The agent management extension."
+    }
+}
+		`)
+
+		ext, err := Get(ServiceClient(), "agent").Extract()
+		th.AssertNoErr(t, err)
+
+		th.AssertEquals(t, ext.Updated, "2013-02-03T10:00:00-00:00")
+		th.AssertEquals(t, ext.Name, "agent")
+		th.AssertEquals(t, ext.Namespace, "http://docs.openstack.org/ext/agent/api/v2.0")
+		th.AssertEquals(t, ext.Alias, "agent")
+		th.AssertEquals(t, ext.Description, "The agent management extension.")
+	})
+}
diff --git a/openstack/common/extensions/results.go b/openstack/common/extensions/results.go
new file mode 100644
index 0000000..2b8d8b7
--- /dev/null
+++ b/openstack/common/extensions/results.go
@@ -0,0 +1,73 @@
+package extensions
+
+import (
+	"fmt"
+
+	"github.com/mitchellh/mapstructure"
+	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/pagination"
+)
+
+// GetResult temporarility stores the result of a Get call.
+// Use its Extract() method to interpret it as an Extension.
+type GetResult struct {
+	gophercloud.CommonResult
+}
+
+// Extract interprets a GetResult as an Extension.
+func (r GetResult) Extract() (*Extension, error) {
+	if r.Err != nil {
+		return nil, r.Err
+	}
+
+	var res struct {
+		Extension *Extension `json:"extension"`
+	}
+
+	err := mapstructure.Decode(r.Resp, &res)
+	if err != nil {
+		return nil, fmt.Errorf("Error decoding OpenStack extension: %v", err)
+	}
+
+	return res.Extension, nil
+}
+
+// Extension is a struct that represents an OpenStack extension.
+type Extension struct {
+	Updated     string        `json:"updated"`
+	Name        string        `json:"name"`
+	Links       []interface{} `json:"links"`
+	Namespace   string        `json:"namespace"`
+	Alias       string        `json:"alias"`
+	Description string        `json:"description"`
+}
+
+// ExtensionPage is the page returned by a pager when traversing over a collection of extensions.
+type ExtensionPage struct {
+	pagination.SinglePageBase
+}
+
+// IsEmpty checks whether an ExtensionPage struct is empty.
+func (r ExtensionPage) IsEmpty() (bool, error) {
+	is, err := ExtractExtensions(r)
+	if err != nil {
+		return true, err
+	}
+	return len(is) == 0, nil
+}
+
+// ExtractExtensions accepts a Page struct, specifically an ExtensionPage struct, and extracts the
+// elements into a slice of Extension structs.
+// In other words, a generic collection is mapped into a relevant slice.
+func ExtractExtensions(page pagination.Page) ([]Extension, error) {
+	var resp struct {
+		Extensions []Extension `mapstructure:"extensions"`
+	}
+
+	err := mapstructure.Decode(page.(ExtensionPage).Body, &resp)
+	if err != nil {
+		return nil, err
+	}
+
+	return resp.Extensions, nil
+}
diff --git a/openstack/common/extensions/urls.go b/openstack/common/extensions/urls.go
new file mode 100644
index 0000000..e31e76c
--- /dev/null
+++ b/openstack/common/extensions/urls.go
@@ -0,0 +1,13 @@
+package extensions
+
+import "github.com/rackspace/gophercloud"
+
+const version = "v2.0"
+
+func extensionURL(c *gophercloud.ServiceClient, name string) string {
+	return c.ServiceURL(version, "extensions", name)
+}
+
+func listExtensionURL(c *gophercloud.ServiceClient) string {
+	return c.ServiceURL(version, "extensions")
+}
diff --git a/openstack/common/extensions/urls_test.go b/openstack/common/extensions/urls_test.go
new file mode 100644
index 0000000..2a1e6a1
--- /dev/null
+++ b/openstack/common/extensions/urls_test.go
@@ -0,0 +1,26 @@
+package extensions
+
+import (
+	"testing"
+
+	"github.com/rackspace/gophercloud"
+	th "github.com/rackspace/gophercloud/testhelper"
+)
+
+const endpoint = "http://localhost:57909/"
+
+func endpointClient() *gophercloud.ServiceClient {
+	return &gophercloud.ServiceClient{Endpoint: endpoint}
+}
+
+func TestExtensionURL(t *testing.T) {
+	actual := extensionURL(endpointClient(), "agent")
+	expected := endpoint + "v2.0/extensions/agent"
+	th.AssertEquals(t, expected, actual)
+}
+
+func TestListExtensionURL(t *testing.T) {
+	actual := listExtensionURL(endpointClient())
+	expected := endpoint + "v2.0/extensions"
+	th.AssertEquals(t, expected, actual)
+}