<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
<!-- This component and the accompanying materials are made available under the terms of the License 
"Eclipse Public License v1.0" which accompanies this distribution, 
and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
<!-- Initial Contributors:
    Nokia Corporation - initial contribution.
Contributors: 
-->
<!DOCTYPE concept
  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept xml:lang="en" id="GUID-D80D6D46-27B7-500E-A83C-63EF038606BF"><title>Application Utilities Overview</title><shortdesc>Application utilities is a collection of libraries that provides low level system and application utility APIs to the platform. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody><section><title>Required background</title> <p>Before using the libraries of application utilities, you must be familiar with Symbian Resource File syntax, Symbian Descriptors and <xref href="GUID-9E92EE30-F2E2-5F28-BB2A-391C09EC69D2.dita">ECOM plug-ins</xref>. </p> </section> <section><title>Architecture</title> <p>Application utilities is a collection of libraries and has no architectural structure. </p> <p>The libraries that constitute the Application utilities are: </p> <ul><li id="GUID-876C801A-4AD4-5A0F-8B25-4CE4726732D6"><p> <xref href="GUID-C8BD333E-8384-534B-822B-F61B2F7C8B9F.dita">Basic Application Framework Utilities</xref>  <b>(bafl.dll)</b> - Provides file system utlities, clipboard, command Line Parsing, Descriptor Arrays, Environment Change Notifier, Incremental Matcher, Resource Files, Localised Names of Plug-ins, System Sounds and String Pools. </p> </li> <li id="GUID-EB20AD40-F1D2-5932-BD99-8A10719B700A"><p> <xref href="GUID-D98E984D-69A5-5BA8-89E7-A7CC9FD0C584.dita">Base Services Utility Library</xref>  <b>(bsul.dll)</b> - Provides wrapper APIs to validate messages and handle errors. This improves robustness of system servers under IPC attack and ensures secure client server architecture. The library also creates and parses <filepath>.ini</filepath> files and provides information about cache drives. </p> </li> <li id="GUID-CFF13C7C-779D-54C8-9EFE-78EF6DE2BE12"><p> <xref href="GUID-39D1807D-3AE0-5273-AA3B-80E8F580DC0B.dita">Activity Manager</xref> <b>(Activitymanger.dll)</b> - Allow clients to monitor for user inactivity (idle time), user activity (key press) and implementing functionalities like screensaver and power management and so on. </p> </li> <li id="GUID-DD19D699-6F57-532D-96B4-D90BB574528F"><p> <xref href="GUID-4B8AEE55-1601-5CF8-9DD1-492DAE18F0F8.dita">System Utilities</xref> <b>(Sysutil.dll)</b> - Provides system utility API functions to retrieve software and language package version strings for display purposes, check for free space on a disk drive before file creation or writing and retrieve device type information (phone model) for display purposes. </p> </li> </ul> </section> </conbody></concept>