diff --git a/cmd/tiller/environment/environment.go b/cmd/tiller/environment/environment.go
index 61305e6f7..1845d83c7 100644
--- a/cmd/tiller/environment/environment.go
+++ b/cmd/tiller/environment/environment.go
@@ -12,6 +12,10 @@ var DefaultEngine = GoTplEngine
 // EngineYard maps engine names to engine implementations.
 type EngineYard map[string]Engine
 
+// Get retrieves a template engine by name.
+//
+// If no matching template engine is found, the second return value will
+// be false.
 func (y EngineYard) Get(k string) (Engine, bool) {
 	e, ok := y[k]
 	return e, ok
@@ -49,8 +53,16 @@ type Engine interface {
 //
 // Release storage must be concurrency safe.
 type ReleaseStorage interface {
+	// Get takes a name and returns the accompanying release.
 	Get(key string) (*hapi.Release, error)
+	// Set saves the release with the given name.
 	Set(key string, val *hapi.Release) error
+	// List lists all active (non-deleted, non-superseded) releases.
+	//
+	// To get deleted or superseded releases, use Query.
+	List() ([]*hapi.Release, error)
+	// Query takes a map of labels and returns any releases that match.
+	Query(map[string]string) ([]*hapi.Release, error)
 }
 
 // KubeClient represents a client capable of communicating with the Kubernetes API.
diff --git a/cmd/tiller/environment/environment_test.go b/cmd/tiller/environment/environment_test.go
index e13f4def1..c1d037423 100644
--- a/cmd/tiller/environment/environment_test.go
+++ b/cmd/tiller/environment/environment_test.go
@@ -27,6 +27,14 @@ func (r *mockReleaseStorage) Set(k string, v *hapi.Release) error {
 	return nil
 }
 
+func (r *mockReleaseStorage) List() ([]*hapi.Release, error) {
+	return []*hapi.Release{}, nil
+}
+
+func (r *mockReleaseStorage) Query(labels map[string]string) ([]*hapi.Release, error) {
+	return []*hapi.Release{}, nil
+}
+
 type mockKubeClient struct {
 }
 
diff --git a/pkg/engine/engine.go b/pkg/engine/engine.go
index 067d6b98a..59a42f96f 100644
--- a/pkg/engine/engine.go
+++ b/pkg/engine/engine.go
@@ -9,7 +9,10 @@ import (
 	"github.com/deis/tiller/pkg/hapi"
 )
 
+// Engine is an implementation of 'cmd/tiller/environment'.Engine that uses Go templates.
 type Engine struct {
+	// FuncMap contains the template functions that will be passed to each
+	// render call. This may only be modified before the first call to Render.
 	FuncMap template.FuncMap
 }
 
diff --git a/pkg/storage/doc.go b/pkg/storage/doc.go
new file mode 100644
index 000000000..21e11ade4
--- /dev/null
+++ b/pkg/storage/doc.go
@@ -0,0 +1,7 @@
+/*Package storage implements storage for Tiller objects.
+
+Tiller stores releases (see 'cmd/tiller/environment'.Environment). The backend
+storage mechanism may be implemented with different backends. This package
+and its subpackages provide storage layers for Tiller objects.
+*/
+package storage
diff --git a/pkg/storage/memory.go b/pkg/storage/memory.go
new file mode 100644
index 000000000..a3670426a
--- /dev/null
+++ b/pkg/storage/memory.go
@@ -0,0 +1,53 @@
+package storage
+
+import (
+	"errors"
+
+	"github.com/deis/tiller/pkg/hapi"
+)
+
+// Memory is an in-memory ReleaseStorage implementation.
+type Memory struct {
+	releases map[string]*hapi.Release
+}
+
+func NewMemory() *Memory {
+	return &Memory{
+		releases: map[string]*hapi.Release{},
+	}
+}
+
+var ErrNotFound = errors.New("release not found")
+
+// Get returns the named Release.
+//
+// If the release is not found, an ErrNotFound error is returned.
+func (m *Memory) Get(k string) (*hapi.Release, error) {
+	v, ok := m.releases[k]
+	if !ok {
+		return v, ErrNotFound
+	}
+	return v, nil
+}
+
+// Set sets a release.
+//
+// TODO: Is there any reason why Set doesn't just use the release name?
+func (m *Memory) Set(k string, rel *hapi.Release) error {
+	m.releases[k] = rel
+	return nil
+}
+
+// List returns all releases
+func (m *Memory) List() ([]*hapi.Release, error) {
+	buf := make([]*hapi.Release, len(m.releases))
+	i := 0
+	for _, v := range m.releases {
+		buf[i] = v
+		i++
+	}
+	return buf, nil
+}
+func (m *Memory) Query(labels map[string]string) ([]*hapi.Release, error) {
+	return []*hapi.Release{}, errors.New("Cannot implement until hapi.Release is defined.")
+}
diff --git a/pkg/storage/memory_test.go b/pkg/storage/memory_test.go
new file mode 100644
index 000000000..7b619b5b0
--- /dev/null
+++ b/pkg/storage/memory_test.go
@@ -0,0 +1,70 @@
+package storage
+
+import (
+	"testing"
+
+	"github.com/deis/tiller/pkg/hapi"
+)
+
+func TestSet(t *testing.T) {
+	k := "test-1"
+	r := &hapi.Release{Name: k}
+
+	ms := NewMemory()
+	if err := ms.Set(k, r); err != nil {
+		t.Fatalf("Failed set: %s", err)
+	}
+
+	if ms.releases[k].Name != k {
+		t.Errorf("Unexpected release name: %s", ms.releases[k].Name)
+	}
+}
+
+func TestGet(t *testing.T) {
+	k := "test-1"
+	r := &hapi.Release{Name: k}
+
+	ms := NewMemory()
+	ms.Set(k, r)
+
+	if out, err := ms.Get(k); err != nil {
+		t.Errorf("Could not get %s: %s", k, err)
+	} else if out.Name != k {
+		t.Errorf("Expected %s, got %s", k, out.Name)
+	}
+}
+
+func TestList(t *testing.T) {
+	ms := NewMemory()
+	rels := []string{"a", "b", "c"}
+
+	for _, k := range rels {
+		ms.Set(k, &hapi.Release{Name: k})
+	}
+
+	l, err := ms.List()
+	if err != nil {
+		t.Error(err)
+	}
+
+	if len(l) != 3 {
+		t.Errorf("Expected 3, got %d", len(l))
+	}
+
+	for _, n := range rels {
+		foundN := false
+		for _, rr := range l {
+			if rr.Name == n {
+				foundN = true
+				break
+			}
+		}
+		if !foundN {
+			t.Errorf("Did not find %s in list.", n)
+		}
+	}
+}
+
+func TestQuery(t *testing.T) {
+	t.Skip("Not Implemented")
+}