new machines appealed to resellers and users. Resellers liked that they could claim more storage space; users liked that they did not have to configure the software. Bundled utilities included (in chronological order): DR DOS 6.0 (1991), from Digital Research, included a custom version of AddStor's SuperStor. PalmDOS 1.0 (1992), from Novell (after acquiring Digital Research), included a DPMS-enabled version of SuperStor. MS-DOS 6.0 (1993), from Microsoft, included DoubleSpace, which was based in part on Vertisoft Systems' DoubleDisk. MS-DOS 6.0 introduced the so-called DOS preload API, an undocumented challenge–response type interface which allowed the disk compression software (DBLSPACE.BIN) to be loaded automatically even before CONFIG.SYS was processed. PC DOS 6.1 (1993), from IBM, while the original release did not include a disk compressor, a custom version of SuperStor/DS (after acquiring AddStor) was included in a later release, also introducing the preload API in the PC DOS line. MS-DOS 6.2 (1993), from Microsoft, included an improved version of DoubleSpace. Novell DOS 7 (1993), from Novell, included a DPMS-enabled version of Stacker 3.12 (STACKER.BIN) from Stac Electronics, which also supported compressed data exchange with remote NetWare and PNW servers also running Stacker in order to avoid unnecessary recompression when copying files. It also introduced support for the DOS 6 preload API in order to maintain compatibility with Microsoft's DoubleSpace in multi-boot scenarios. A similar mechanism was used to load the optional single- or multi-user SECURITY component. PTS-DOS Extended 6.4 (1994), from PhysTechSoft, included a disk compression component named Folder (FOLDER.SYS) PC DOS 6.3 (1994), from IBM, included a version of SuperStor/DS. MS-DOS 6.22 (1994), from Microsoft, included DriveSpace, which was DoubleSpace with a different compression algorithm (DRVSPACE.BIN), after MS-DOS 6.21 had to ship without any disk compression software at all for legal reasons. PC DOS 7.0 (1995), from IBM, included a DPMS-enabled version of Stacker 4.02 from Stac Electronics. Windows 95 (1995), from Microsoft, included an updated version of DriveSpace 2. Windows 95 OSR2 (1996), from Microsoft, included a stripped-down version of DriveSpace 3. Windows 95 Plus! (1996), from Microsoft, included the full version of DriveSpace 3. OpenDOS 7.01 (1997), from Caldera (after acquiring Novell DOS), included a DPMS-enabled version of Stacker 3.12. DR-DOS 7.02 (1998), from Caldera, included a DPMS-enabled version of Stacker 3.12. DR-DOS 7.02 also added support for Microsoft's DriveSpace. PC DOS 2000 (1998), from IBM, included a DPMS-enabled version of Stacker 4.02. Windows 98 (1998), from Microsoft, included