afterglow (Emergency Power System)
Auxiliary capacitor charging and discharging. Tells CSB to punch holes in RLV restrictions for most features, but sets up 'video enabled' mode on its own. Distress beacon functionality.

ambiance (Effects Library)
Bang (formerly 'cortex') commands, particle effects, sound settings. Passes some sound effects commands on to the sound device prim. Boot/halt and menu sounds.

arabesque (Arabesque Script System)
@color and @do.

balance (Configuration Manager)
Handles _oem loading in 8.5+, pipes, and the configuration data store.

bonds (Core Services Bus)
Manages RLV consequences of subsystem states, integrates environmental RLV flags from _restraint as necessary, RLV effects of interference, @audience, remote (/1) commands.

coil (Charging Interface)
Handles all channel 360 messages (ACS charging, interference, SXD charging, and handshaking for the remote control), as well as UMD, Qetesh, and Refactor charging. DDT internal message logging and message name lookup table.

compliance (Internal Restraint Interface)
@vox, @policy.

core (_console-screen)
Main module of _console-screen HUD.

cortex (Cortex)
Chat processing, persona management, preset messages. Sends and receives messages to/from the vox pipeline.

echo (Sound Device)
Loads system voice schemes and plays sound effects from the speaker prim.

ephemera (Guest Manager)
Discrete guest management module introduced in 8.5b6. Previously part of hierarchy. Controls @guests, whitelist/blacklist management, consent, and displaying the consent dialog to the unit.

exhibition (sxdwm Core; deprecated)
Complete single-user menu system. Rewritten for Companion 8.3.

exhibition-core (sxdwm Core)
Loads m4_ menu definition files, executes menu actions, handles updates to m4 menus, manages sessions (by session ID only).

exhibition-dwm (sxdwm Touchscreen Support)
Controls session 0, loads _dwm4-config

exhibition-tty (sxdwm Dialog Support)
Creates dialogs for the user when asked. Normally creates new sessions (numbered 1 or higher) but can take over session 0 temporarily if requested by exhibition-dwm.

extended (_console-native)
Analog to subs script from _console-screen. Handles pop-outs for Stallion, Akashic Icons, Configuration, and other miscellaneous features.

foundation (BIOS)
Start up and shut down, _oem file reading, power profiles, @about, redirect of messages to user memory prim, manages color and brightness of screen prim.

General
Issues that affect multiple components, or some aspect of the system not represented by a component. Refactoring operations should be filed under the recipient component.

hierarchy (Network Security Manager)
@domain functionality. Guest access and consent are now in the ephemera module.

interface (_console-native)
Rendering backend for _console-native HUD. Manages altimeter and placement of major HUD elements.

interface (_console-screen)
Layout engine for _console-screen HUD.

laserline (_console-native)
Target-tracking module in the _console-native HUD.

navigator (Navigation Manager)
@follow, @navigate, @leash, @unleash, and related functions.

obedience (Access Manager)
@help, @commands, bolts, PIN entry, gender, authority.

power (Subsystem Manager)
Battery withdrawal, which subsystems are officially enabled/disabled/unavailable, external load management, FTL capacitor.

protocol (_console-native)
Manages device interface messages, menus, and most functionality in the _console-native HUD.

puppet (Device Manager)
Handling of all standard light bus messages. Tracking and registration of active peripherals.

restraint (External Restraint Interface)
RLV relay component.

songbird (Disk Driver and Filesystem Manager)
Bazaar memory card ejection/loading (8.5+?), reading of persona files, listing of installed packages, delivery of info notecards, execution of uninstall manifests, tutorial system, manages PIN of memory card prim, app menu (8.5m3).

submission (User and Security Manager)
User list and owner list tracking, primary resolution of permissions that a key has, most interaction with keychain storage. (Some other commands may handle user-specific features by making a 222 request)

subs (_console-screen)
Because _core was full. Pop-up sub-HUDs for Emotion, Akashic Icons, etc.

transceiver (Central Communications Interface)
Manages @audience, XNMS, and other network protocols in 8.6+.

whip (Task Scheduler)
Thaws/hibernates library modules, tracks module capabilities, and active tasks. @tasks, @reset, @module, and the new 8.5 (ATOS 12.1) command dispatcher.

xanadu-client (Package Manager)
Xanadu package server connectivity, manages PIN of root prim, user interface for listing/removing/installing packages.