Disk First Aid is a free software utility made by which organzation, that was bundled with all computers running the classic Mac OS, this tool verifies and repairs a limited number of directory structure problems on any HFS or HFS Plus hard disk or volume?
Apple Inc.
Disk First Aid
Disk First Aid is a free software utility made by Apple Inc. that was bundled with all computers running the classic Mac OS.
 This tool verifies and repairs a limited number of directory structure problems on any HFS or HFS Plus hard disk or volume.
HFS Plus
HFS Plus or HFS+ is a file system developed by Apple Inc. It served as the primary file system of macOS.
 HFS+ was developed to replace the Hierarchical File System (HFS) as the primary file system used in Macintosh computers (or other systems running the classic Mac OS).
 It is also one of the formats used by the iPod digital music player.
 HFS Plus is also referred to as Mac OS Extended or HFS Extended, where its predecessor, HFS, is also referred to as "Mac OS Standard" or "HFS Standard".
 During development, Apple referred to this file system with the codename "Sequoia".
 At WWDC 2017, Apple announced macOS High Sierra, in which the default file system of Mac is changed to APFS.
Retrospect (software)
Retrospect is a family of software applications that backup computers running the macOS, Microsoft Windows, Linux, and classic Mac OS operating systems.
 It uses the client–server backup model, which means there must be a backup server application running on one computer and small-footprint client applications running on the other computers being backed up in a heterogeneous network.
 The destination may be a tape drive instead of a hard disk drive or cloud drive.
 Retrospect's backup server application runs on either a macOS or a Windows computer, but there are also versions of the client application that run on Linux or classic Mac OS. Hierarchical File System
Hierarchical File System (HFS) is a proprietary file system developed by Apple Inc. for use in computer systems running Mac OS.
 Originally designed for use on floppy and hard disks, it can also be found on read-only media such as CD-ROMs. HFS is also referred to as Mac OS Standard (or, erroneously, "HFS Standard"), while its successor, HFS Plus, is also called "Mac OS Extended" (or, erroneously, "HFS Extended"). Volume Table of Contents
In the IBM mainframe storage architecture, Volume Table of Contents, or VTOC, is a data structure that provides a way of locating the data sets that reside on a particular disk volume.
 It is the functional equivalent of both the Master Boot Record (MBR) or GUID Partition Table (GPT) on a desktop PC, and the root directory of a mass storage device (floppy, jump drive, hard disk, etc.) on a PC or minicomputer, e.g. / on Unix or Linux, C:\ on DOS or Windows.
 It lists the names of each data set on the volume as well as size, location, and permissions.
 Additionally, it contains an entry for every area of contiguous free space on the volume.
 The third record on the first track of the first cylinder of any volume of DASD (i.e. disk pack) is known as the volume label and must contain a pointer to the location of the VTOC.
 A VTOC is added to a disk when it is initialized using the Device Support Facilities utility program, ICKDSF.
 VTOC was originally designed for removable disk packs. Drive Setup
Drive Setup is the default disk formatting tool in Mac OS 7.5.2-9.2.2.
 It supports such features as partitioning, and low-level formatting.
 It could format hard drives in HFS, HFS Plus file systems, and supported formatting drives for use with Linux and A/UX. FileSalvage
FileSalvage is a data recovery product produced by SubRosaSoft.com Inc. It is a Mac OS X application used to recover lost data from hard disk drives, USB flash drives, CD-ROMs, and other media.
 FileSalvage is device and file system independent and supports recovery from drives formatted for all Mac OS X file system types, including HFS, HFSX and HFS+ as well as FAT12/16/32, NTFS/NTFS5, ext2fs and other file system types. Apple HD SC Setup
Apple HD SC Setup was a small software utility that was bundled with various versions of the classic Mac OS and A/UX operating systems made by Apple Computer.
 Introduced with Apple's first SCSI hard drive, the Hard Disk 20SC in September 1986, Apple HD SC Setup can update drivers and partition and initialize hard disks.
 It was often used when reinstalling the operating system of an Apple Macintosh computer, or to repair corrupt partition information on a SCSI hard disk.
 Prior to its introduction, formatting of disks was handled exclusively by the Mac's Finder application, or third party formatting utility software customized for a specific disk drive. System Information (Mac)
System Information (previously known as System Profiler) is a software utility derived from field service diagnostics produced by Apple's Service Diagnostic Engineering team, at that time located in Apple satellite buildings in Campbell, California, that was bundled with the classic Mac OS since Mac OS 7.6 under the name Apple System Profiler.
 In Mac OS X v10.0, the first release of macOS, it was renamed System Profiler; with the release of Mac OS X 10.7 "Lion" it was again was renamed to System Information.
 Other new features in Lion are the ability to look up support information for the user's hardware model as well.
 In OS X Mountain Lion and later versions of macOS users can also access System Information by holding down the option key and "System Information..." will replace "About This Mac" in the Apple Menu. Self mounting image
A self mounting image is a disk image format, commonly found on the classic Mac OS platform, that is encapsulated in an application that mounts it as a file system.
 When downloaded from the Internet, they are often in a BIN, BinHex or StuffIt file.
 Despite being an application, they often have a .
smi file extension.
 Disk Copy, the application commonly used to handle disk images in the classic Mac OS was an optional program not part of the standard installation.