Disk images have long been the standard and preferred way of handling information transfer over the Internet on the Mac. This is especially true when it comes to applications. Almost every application I see comes as a disk image, and for obvious reasons. It's small, efficient, you can mount it quickly and unmount it when you are done, and it can be handled by the system, without the need for additional software. For things other than software, zip archives are still pretty much standard, because of their cross platform and widespread compatibility. However, when it comes to sharing information with other Mac users, or simply sorting your own information, there is nothing like disk images. While the tool Apple provides for creating these is adequate, it is still not exactly the best way of creating images, with some third party solutions offering a better handling, such as FreeDMG.

What it is
This program is quite a number of things, and can be used in many different ways, all related to disk images. To sum it up, this program can be used to create new disk images, and to modify existing ones.

Each of these two broad purposes has many sub component and options, and the program itself is quite a complex tool, which is a bit of a problem since it lacks proper documentation.

Creating disk images
This task can be handled in several ways. You can create a new image and then load it with content, or you can create a disk image starting from a certain file or folder. Both the application’s main window and the dock icon support drag and drop so you can also make use of that quite heavily.

There is quite a number of compression formats to choose from, and you can also choose from several file systems, including MS-DOS and UFS. In addition, you can also opt to encrypt the disk image for added security.

Creating disk images from existing content will make them a certain size, however, you can also create empty sparse images. This means they can be of any size and will automatically grow or shrink in size to accommodate their contents. This is one of the better ways to go about this process, as these images can later be converted using the same program into a standard, read/write image.

Working with existing disk images
One of the biggest pains in working with disk images is finding out you need more space, or having to change the disk image type. Usually, this means creating a totally new image and moving the content from the old one to the new one in order to keep working. This is fine, as long as it doesn’t happen too often, however, if it starts repeating, this can turn into a major problem that can turn people away from using the disk image.

Fortunately, FreeDMG offers a lot of tools that deal with existing disk images. You can convert existing images, changing their type and encryption, if necessary. This is great for changing a set image to a sparse one or the other way around. It is also a way of making disk images that are usable in Classic, a problem I had run across a few years ago and was never able to get around.
You can also resize existing disk images, making them bigger or smaller, without having to create a new image, and there is also the ‘minimize’ option that will resize the disk image to take the smallest possible size to fit its contents.
Other operations include segmenting large disk images into multiple smaller ones, as well as burning disk images and changing their password.

Other useful tools deal with the diagnosing of existing images, letting you see all the relevant information about any given disk image as well as the ability to verify their integrity by means of checksums.

The program also has several features such as the ‘make internet ready’ option, which are a bit ambiguous, as nothing is said about it, and it is unclear exactly what it does. The old documentation issue is present here yet again, with the program having virtually no written documentation that could help someone who is new to disk images get started.

The Good
Many options for both creating new disk images and modifying existing ones. Gives a lot more control to the user than the default Disk Image tool.

The Bad
Inadequate documentation becomes a real issue, especially with functions that are a bit unclear. Other than this, the program is top notch.

The Truth
A one stop solution to everything disk image related. Has enough flexibility to let you work any way you want with disk images.