This article comprises the What's New in Version 7.5.3 Read Me.

If you already have System 7.5 and are installing to update to version 7.5.3, the following new features are available (either with the Easy Install option, or for OpenDoc, with its own Installer):

• All previously-installed system software components are updated to the latest versions, including any components that you disabled using the Extensions Manager. You will also find performance improvements for some PowerPC-based computers. Some of these improvements are due to the addition of more native system software components, including Apple Guide, the Resource Manager, and the SCSI Manager.
• When dragging icons on PowerPC computers, you will see a translucent image of the icon instead of an outline.
• A new version of Drive Setup (version 1.0.4) fixes a problem that occurred with some types of IDE hard disks. If you use an IDE (ATA) hard disk, you should update your driver as part of the installation of this software. When using Drive Setup on some IDE hard disks, the Update driver, Customize volume, and Test disk options are dimmed. To use these options, back up all data from the IDE disk onto another disk, and use Drive Setup to reinitialize the IDE disk.
• Open Transport networking software provides improved network flexibility and performance. Open Transport is available on all computers with 68030, 68040, or PowerPC processors, except for the desktop 5200, 5300, 6200, and 6300 series computers. Open Transport may require more RAM than classic AppleTalk.
  
  After you install system software version 7.5.3, Open Transport will be turned on only if you were using it before you installed the new system software. You can turn on Open Transport with the Network Software Selector program (in the Apple Extras folder after you install the new system software).
  
  For more information, see the Open Transport Information folder, inside the Apple Extras folder.
• Text-to-Speech software is automatically installed. If you don't use this software, you can use the Extensions Manager to turn off MacInTalk (version 2 or 3) and the Speech control panel.
• You have the option to install OpenDoc, a new plug-in software architecture for the Mac OS. OpenDoc technology supports a new type of software called a part. You use parts to easily add new features to your applications. You add features by dragging parts into documents created by any OpenDoc-aware application. You can also create documents entirely out of OpenDoc parts. A variety of these parts will be available from both Apple and third-party sources, including parts for placing Internet resources directly into documents. No parts come with this upgrade kit.
• When you rebuild the desktop, comments typed in a file's Get Info window are no longer deleted.
• Many previously-released fixes are also included in this system software version, including those in the 7.5.2 Printing Update, the PowerBook 5300 System Software Update, the PowerBook 2300c Update, System 7.5 Update 2.0, and System 7.5.3 Revision 2.