Connectix RAM Doubler (1996) 3 Utility MacOS

RAM Doubler is a utility for Windows 3.1 that uses advanced resource management and memory compression techniques to allow more applications to run side by side. It was designed to be simple and easy to use compared to some competing programs. It competed against similar tools such as SoftRam, Hurricane, and MagnaRam

• Mac OS

DiskDoubler (1990) 0 Utility Archive MacOS

DiskDoubler is an automated file compression program for the Apple Macintosh. It does not compress the entire drive, but rather specified files. It automatically compresses and recompresses files as you use them.

• 3.x

Double Helix (1986) 0 Database MacOS

Helix/Double Helix is an easy to use relational database for the Apple Macintosh. It features a visual programming system, and options for multiuser over AppleTalk.

• 1.0

DoubleDisk (1991) 2 Utility DOS

First released in 1989, DoubleDisk was the first real-time drive compression product for DOS. It is a fairly no-frills program and sticks to what it does best. It was relatively low cost compared to its later competitors. and Expandz! Plus

• 2.5
• 2.6

DoubleDOS (1984) 4 Utility DOS

DoubleDOS is a simple and easy to use multitasking tool for DOS. It can preemptively run up to two DOS programs at a time. Its main advantage is that it requires very little RAM overhead compared to other multitasking or task switching environments. Because DOS programs can and usually do bypass OS calls, many programs must be "patched" in order to work. things at once, then this would have been a good choice. Reportedly, the first version may have worked with DOS 1.x.

• 2.x
• 4.02