ADF File

What are ADF files and how to open them

Are you having problems opening an ADF file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your ADF files.

What is an ADF file?

ADF files have multiple uses, and Act! Database is one of them. Read more about the other uses further down the page.

Act! Database

Act!, previously Sage Act, is a marketing and CRM software solution. They name their database files using the .adf file extension.

How to open ADF files

We have identified one ADF opener that is compatible with this specific type of ADF file.

Programs that open Act! Database files

Last updated: August 17, 2026

All known file formats using extension .ADF

While Act! Database is a popular type of ADF-file, we know of 15 different uses of the .ADF file extension. Different software may use files with the same extension for different types of data.

ARIS Document File

These ADF files contain flowcharts and diagrams created in ARIS, a Java-based application used to manage and analyze your business processes.

ADF opener for Windows

We have identified one ADF opener that is compatible with this specific type of ADF file.

SNAP Archive Data File

These ADF files are archive files created in SNAP Surveys, an online survey management service.

ADF files consist of the MDF (Metadata File) and the RDF (Raw Data File). Snap Surveys use this file type to help you run surveys that you can either store or share the data you collect. You can use Snap WebHost to run and manage online surveys.

While we have not verified the apps ourselves yet, our users have suggested ten different ADF openers which you will find listed below.

ABackup Backup Disk Image

We know that one ADF format is ABackup Backup Disk Image. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Acorn ADFS Disk Image

These ADF files contain the content of floppy and hard drives from Acorn computers. You can load these ADF files on your PC by using an Acorn emulator or ADFS Explorer. The Master 128 range of computers used ADFS as one of their disk file systems.

Actual Drawing Project

Actual Drawing Project ADF is the native project file format used by Actual Drawing, a visual web authoring tool made by PY Software. It stores complete information about one website‐design project, including layout data, graphics, text, and settings, so that a user can resume editing their page designs inside Actual Drawing.

Actual Drawing writes ADF files when you save a project; the program uses them internally until you export to HTML or upload your content via FTP. The saved ADF contains everything needed to reproduce the page visually and functionally inside Actual Drawing, including graphics properties (e.g. shadows, opacity), text formatting, image effects, and internal preview data.

ADF files for this format include internal identifiers to ensure the correct file format is being read. For example, starting at offset 2 is an ASCII string "ActualDrawingv", and the file contains strings such as "PREVIEW JPEG IMAGE.", "ACTUAL DRAWING V.", ".HTML", and "JFIF".

Ad Designer Project

The Ad Designer Project file format stores a draft or working version of an advertisement design created with the Ad Designer program. These files are used by Ad Designer to save all layout elements, image previews, HTML placeholders, version metadata, and embedded preview images while the design is being developed. The working design saved in a .ADF file is intended for further editing and refinement before final export to formats like HTML, JPEG, or other ad-delivery formats.

Ad Designer writes .ADF files when you choose "Save Project" (or similar) from within the program. The user can then reopen that same .ADF in Ad Designer to continue editing - adjusting layout, replacing graphics, editing text, or changing ad behavior. Once the design is complete, the file is typically exported into standard web ad formats (HTML5, JPEG, animated GIF, etc.) for publishing or delivery to ad networks.

The format is identifiable internally: early in the file at offset 2 there is the ASCII sequence "AdDesignerv" (representing "Ad Designer v..."). The file also contains strings such as "PREVIEW JPEG IMAGE.", "AD DESIGNER V.", ".HTML", and "JFIF", which reflect the embedded preview image section, version designation, HTML content, and JPEG image metadata respectively.

Advanced Data Format Database

These ADF files contain numerical data that is stored in an Advanced Data Format Database. ADF files consist of nodes, and each node follows the same rules: There is one "central root", every child node has a parent, and the root node has no parent. The nodes form a tree structure to allow for multiple file branching. When opening an ADF file, the root receives information from the calling program to access the tree. A search gets run on the tree to find the needed information or to store new data.

Ami-Back Backup Disk Image

We know that one ADF format is Ami-Back Backup Disk Image. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Amiga Disk image File

These ADF files contain the disk images used by the Amiga home computers and emulators. ADF files are typical images of the Amiga-formatted track, held on the 880 KiB disk. EasyADF is an app that allows you to download ADF files and copy them onto your Amiga disk. ADF Opus, a Windows-based program, will enable you to create your own ADF files. Acorn also used these ADF files in their computers and emulators.

Amiga Kickstart Disk Image

Amiga Kickstart Disk Image files store a copy of the Amiga Kickstart firmware as it was distributed on floppy disk so an Amiga system can boot without built-in ROM. On the original Amiga 1000 (released 1985), Kickstart versions 1.x were shipped on floppy disks, which, when inserted, load about 256 KB of core firmware into a special RAM area called the writable control store before Unix-type files or games begin loading. Later Amiga models used Kickstart in ROM chips, but disk-based Kickstart remained useful for the Amiga 1000 and early A3000s.

These .ADF images are created by reading a Kickstart floppy disk sector-by-sector into a standard "Amiga Disk File" image. Once in ADF form the image can be used with emulators or written back to a physical Amiga floppy disk. Using such an image lets one boot an original A1000 (or A3000 configured accordingly), load that Kickstart version, and then continue booting operating system components like Workbench from floppy or hard disk. Care must be taken that the ADF image matches the exact Kickstart revision and correct boot format for the intended machine.

A technical signature helps distinguish these disk images: they start with the four ASCII bytes "KICK" at file offset 0, immediately followed by a replicated copy of the Kickstart ROM data (usually 256 KB for versions before AmigaOS 2.0, or 512 KB in later ROMs) and often include the string "AMIGA ROM OPERATING SYSTEM AND LIBRARIES" within the image. Sectors beyond the ROM data are unused in many images.

Antenna Data File

Antenna Data File is a plain-text file format defined by NSMA Recommendation WG 16.99.050 for storing detailed antenna pattern and specification data. It's used to share complete characterization of an antenna: frequency response, radiation patterns in azimuth and elevation cuts, gain, front-to-back ratio, mechanical dimensions, polarization, tilt, and other properties relevant for RF engineering. Each file represents data for one antenna, possibly at multiple frequencies, and is intended for use by engineers in planning, coordination, measurement, or analysis of antenna systems.

These .ADF files are created by antenna manufacturers or certification/measurement labs producing pattern data, and are consumed by RF design and planning tools, propagation software, antenna-pattern editors, or visualization tools. Tools like Pathloss's AntRad and antenna pattern viewer programs read these files to plot the antenna cuts and derive metrics like beamwidth, gain, or antenna tilt.

Files follow a fixed field order. They begin with a signature line like "REVNUM:, NSMA WG16.99.050", and contain named fields such as ANTMAN, MODNUM, LOWFRQ, HGHFRQ, GUNITS, MDGAIN, AZWIDT, ELWIDT, ATVSWR, ELTILT, NUMCUT, PATCUT, NUPOIN, etc., followed by pattern cut data - lines of angle and gain values.

PS/2 MicroChannel Adapter Description File

These ADF files contain the configuration information of the MicroChannel Adapter card. ADF files are text files that store information about the card's memory addressing and interrupts.

MicroChannel cards were the basis of early plug-and-play systems. You insert your MCA card with a custom floppy disk (this came with your pc) to add new cards (video, memory, printer, etc.) to your pc.

This allowed you to add new cards to your original hardware without the help of an expensive technician. The downside was that you could not add or change your PC's cards if you do not have the custom floppy disk.

You usually do not need to edit or view these files, as they only contain information usable by the software program that uses them.

Robot Arena Hazard Configuration

Robot Arena Hazard Configuration files store information about the hazards present in an arena in the game Robot Arena (also known as Robot Arena 2: Design & Destroy). These files define what hazards are in each arena - such as saws, spikes, flame throwers or pits - their positions, activation behavior, and other settings. When you select an arena in the game, the .ADF file tells the game engine what dangerous elements should be active and where to place them.

These files are created by the game (or its map/arena editor if available) and read by the game runtime when loading an arena. Players might encounter these when modding the game, customizing arenas, or downloading user-created arenas. If the game crashes or fails to show hazards in an arena, the .ADF file may be missing, corrupted, or incompatible with the version of the game you are running.

Internally the format begins with a header identifying it as a hazard configuration file. At byte offset 0, it holds the ASCII sequence: ADF followed by CR LF CR LF then "[Hazard Configuration]" (i.e. "ADF....[HazardConfiguration]"). It includes strings like "HAZARDPOINT01" to mark specific hazard points.

SuperDOS Adapter File

These ADF files contain the information and configuration of the BlueBird SuperDOS, a multi-tasking multi-user operating system used to run business applications over a "dumb" terminal. This replaced expensive minicomputers with a single PC.

The SuperDos ADF file runs when you boot your PC. BlueBird SuperDOS assisted car rental agencies and movie/storage companies to reduce the number of expensive computers on every desk.

Various apps that use files with this extension

These apps are known to open certain types of ADF files. Remember, different programs may use ADF files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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