diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index b3b4b9a..40641f5 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -12,12 +12,13 @@
 
 - [System overview](./operation/index.md)
 - [The System Bus: syndicate-server](./operation/system-bus.md)
-  - [Bus scripting language](./operation/scripting.md)
+  - [Services and service dependencies](./operation/service.md)
   - [Built-in services and service classes](./operation/builtin/index.md)
     - [Gatekeeper](./operation/builtin/gatekeeper.md)
     - [TCP/IP and Unix-socket Transports](./operation/builtin/relay-listener.md)
     - [Configuration watcher](./operation/builtin/config-watcher.md)
-    - [Process supervision and management](./operation/builtin/daemon.md)
+    - [Daemons and external programs](./operation/builtin/daemon.md)
+  - [Configuration scripting language](./operation/scripting.md)
 - [Configuration files and directories]()
   - [The boot layer]()
     - [Logging]()
diff --git a/src/glossary.md b/src/glossary.md
index 88eb238..c0d942d 100644
--- a/src/glossary.md
+++ b/src/glossary.md
@@ -3,9 +3,9 @@
 ## Actor
 ## Assertion
 ## Attenuation
-## Bus Scripting Language
 ## Capability
 ## Compositional
+## Configuration Scripting Language
 ## Conversational State
 ## Dataspace
 ## E
diff --git a/src/operation/builtin/index.md b/src/operation/builtin/index.md
index 62c1525..8284d21 100644
--- a/src/operation/builtin/index.md
+++ b/src/operation/builtin/index.md
@@ -1 +1,3 @@
 # Built-in services and service classes
+
+The `syndicate-server` program 
diff --git a/src/operation/index.md b/src/operation/index.md
index b137f13..8aab167 100644
--- a/src/operation/index.md
+++ b/src/operation/index.md
@@ -7,7 +7,6 @@ tree](../glossary.md#supervision-tree), conceptually rooted at the [system
 bus](./system-bus.md) (NB. not at PID 1).
 
 ```ditaa system-supervision-tree
-(Example)
               +----------------------------------+
               |Root System Bus (syndicate–server)|
               +----------------+-----------------+
diff --git a/src/operation/scripting.md b/src/operation/scripting.md
index 088b83f..0d8a77e 100644
--- a/src/operation/scripting.md
+++ b/src/operation/scripting.md
@@ -1 +1 @@
-# Bus scripting language
+# Configuration scripting language
diff --git a/src/operation/service.md b/src/operation/service.md
new file mode 100644
index 0000000..68d05d2
--- /dev/null
+++ b/src/operation/service.md
@@ -0,0 +1 @@
+# Services and service dependencies
diff --git a/src/operation/system-bus.md b/src/operation/system-bus.md
index 0bb413c..b105838 100644
--- a/src/operation/system-bus.md
+++ b/src/operation/system-bus.md
@@ -6,26 +6,36 @@
 The `syndicate-server` program has a number of closely-related functions. In many ways, it is a
 reification of the [system layer concept](../glossary.md#system-layer) itself.
 
- 1. It provides a root **system bus** service for use by other programs. In this way, it is
+It provides:
+
+ 1. A **[root system bus](#the-root-system-bus)** service for use by other programs. In this way, it is
     analogous to D-Bus.
 
- 2. It provides a [**gatekeeper** service](./builtin/gatekeeper.md), for exposing
+ 2. A general-purpose **[service dependency tracking facility](./service.md)**.
+
+ 3. A [**gatekeeper** service](./builtin/gatekeeper.md), for exposing
     [capabilities](../glossary.md#capability) to running objects as (potentially long-lived)
     [macaroon](../glossary.md#macaroon)-style "sturdy references", plus TCP/IP- and
     Unix-socket-based **[transports](./builtin/relay-listener.md)** for accessing capabilities
     through the gatekeeper.
 
- 3. It provides a limited **[configuration scripting language](./scripting.md)** suitable for
+ 4. A limited **[configuration scripting language](./scripting.md)** suitable for
     programming [dataspaces](../glossary.md#dataspace) with simple reactive behaviours.
 
- 4. It provides an [`inotify`](https://en.wikipedia.org/wiki/Inotify)-based **[configuration
+ 5. An [`inotify`](https://en.wikipedia.org/wiki/Inotify)-based **[configuration
     loader](./builtin/config-watcher.md)** which loads and executes configuration files written
     in the scripting language.
 
- 5. It provides [**process supervision** and **dependency tracking**](./builtin/daemon.md)
-    services for starting other programs.
+ 6. [**Process startup and supervision**](./builtin/daemon.md)
+    services for running external programs.
 
-## The main system bus
+The program can also be used as an "inferior" bus. For example, there may be a per-user bus, or
+a per-session bus, or both. Each bus would appropriately scope the lifetime of its supervised
+processes.
+
+Finally, it can be used completely standalone, outside a Synit context.
+
+## The root system bus
 
 The [`synit-pid1`](./index.md#sbinsynit-pid1) program invokes `syndicate-server` like this: