diff --git a/Doxyfile b/Doxyfile
index 9e298157..677d8b47 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -342,7 +342,7 @@ OPTIMIZE_OUTPUT_SLICE  = NO
 #
 # Note see also the list of default file extension mappings.
 
-EXTENSION_MAPPING      =
+EXTENSION_MAPPING      = js=javascript
 
 # If the MARKDOWN_SUPPORT tag is enabled then doxygen pre-processes all comments
 # according to the Markdown format, which allows for more readable
@@ -944,9 +944,14 @@ WARN_LOGFILE           =
 # Note: If this tag is empty the current directory is searched.
 
 INPUT                  = README.md \
+                         core/app.js \
+                         core/core.js \
+                         core/http.js \
                          docs/ \
                          src/
 
+# Not yet: core/tfrpc.js core/client.js
+
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
 # libiconv (or the iconv built into libc) for the transcoding. See the libiconv
@@ -986,6 +991,7 @@ INPUT_FILE_ENCODING    =
 # *.f18, *.f, *.for, *.vhd, *.vhdl, *.ucf, *.qsf and *.ice.
 
 FILE_PATTERNS          = *.h \
+                         *.js \
                          *.md
 
 # The RECURSIVE tag can be used to specify whether or not subdirectories should
diff --git a/core/core.js b/core/core.js
index 0b34bb71..77081405 100644
--- a/core/core.js
+++ b/core/core.js
@@ -1,12 +1,25 @@
+/**
+** \defgroup tfcore Tilde Friends Core JS
+** Tilde Friends process management, in JavaScript.
+** @{
+*/
+
 import * as app from './app.js';
 import * as http from './http.js';
 
+/** All running processes. */
 let gProcesses = {};
+/** Whether stats are currently being sent. */
 let gStatsTimer = false;
+/** Effectively a process ID. */
 let g_handler_index = 0;
-
+/** Time between pings, in milliseconds. */
 const k_ping_interval = 60 * 1000;
 
+/**
+** Print an error.
+** @param error The error.
+*/
 function printError(error) {
 	if (error.stackTrace) {
 		print(error.fileName + ':' + error.lineNumber + ': ' + error.message);
@@ -19,6 +32,12 @@ function printError(error) {
 	}
 }
 
+/**
+** Invoke a handler.
+** @param handlers The handlers on which to invoke the callback.
+** @param argv Arguments to pass to the handlers.
+** @return A promise.
+*/
 function invoke(handlers, argv) {
 	let promises = [];
 	if (handlers) {
@@ -39,6 +58,12 @@ function invoke(handlers, argv) {
 	return Promise.all(promises);
 }
 
+/**
+** Broadcast a named event to all registered apps.
+** @param eventName the name of the event.
+** @param argv Arguments to pass to the handlers.
+** @return A promise.
+*/
 function broadcastEvent(eventName, argv) {
 	let promises = [];
 	for (let process of Object.values(gProcesses)) {
@@ -49,6 +74,11 @@ function broadcastEvent(eventName, argv) {
 	return Promise.all(promises);
 }
 
+/**
+** Send a message to all other instances of the same app.
+** @param message The message.
+** @return A promise.
+*/
 function broadcast(message) {
 	let sender = this;
 	let promises = [];
@@ -65,6 +95,15 @@ function broadcast(message) {
 	return Promise.all(promises);
 }
 
+/**
+** Send a message to all instances of the same app running as the same user.
+** @param user The user.
+** @param packageOwner The owner of the app.
+** @param packageName The name of the app.
+** @param eventName The name of the event.
+** @param argv The arguments to pass.
+** @return A promise.
+*/
 function broadcastAppEventToUser(
 	user,
 	packageOwner,
@@ -87,6 +126,11 @@ function broadcastAppEventToUser(
 	return Promise.all(promises);
 }
 
+/**
+** Get user context information for a call.
+** @param caller The calling process.
+** @param process The receiving process.
+*/
 function getUser(caller, process) {
 	return {
 		key: process.key,
@@ -97,12 +141,26 @@ function getUser(caller, process) {
 	};
 }
 
+/**
+** Send a message.
+** @param from The calling process.
+** @param to The receiving process.
+** @param message The message.
+** @return A promise.
+*/
 function postMessageInternal(from, to, message) {
 	if (to.eventHandlers['message']) {
 		return invoke(to.eventHandlers['message'], [getUser(from, from), message]);
 	}
 }
 
+/**
+** Get or create a process for an app blob.
+** @param blobId The blob identifier.
+** @param key A unique key for the invocation.
+** @param options Other options.
+** @return The process.
+*/
 async function getProcessBlob(blobId, key, options) {
 	let process = gProcesses[key];
 	if (!process && !(options && 'create' in options && !options.create)) {
@@ -652,6 +710,10 @@ ssb.addEventListener('connections', function () {
 	broadcastEvent('onConnectionsChanged', []);
 });
 
+/**
+** Load settings from the database.
+** @return The settings as a key value pairs object.
+*/
 async function loadSettings() {
 	let data = {};
 	try {
@@ -670,6 +732,9 @@ async function loadSettings() {
 	return data;
 }
 
+/**
+** Send periodic stats to all clients.
+*/
 function sendStats() {
 	let apps = Object.values(gProcesses)
 		.filter((process) => process.app)
@@ -685,6 +750,16 @@ function sendStats() {
 	}
 }
 
+/**
+** Invoke an app's handler.js.
+** @param response The response object.
+** @param app_blob_id The app's blob identifier.
+** @param path The request path.
+** @param query The request query string.
+** @param headers The request headers.
+** @param package_owner The app's owner.
+** @param package_name The app's name.
+*/
 exports.callAppHandler = async function callAppHandler(
 	response,
 	app_blob_id,
@@ -750,4 +825,6 @@ exports.callAppHandler = async function callAppHandler(
 	response.end(answer?.data);
 };
 
-export {invoke, getProcessBlob};
+/** @} */
+
+export { invoke, getProcessBlob };