Dreamlinux started off as a project which was proof of concept regarding a script called MkDistro written by nelsongs. The script would allow any user to take a base distro, customize it and then create a bootable iso of their creation.
It's first encarnation was a Knoppix/Debian base (the 2.X series) which progressed to the new 3.X series which is pure Debian (Lenny/Testing to be precise).
Derivatives and Forks
Dreamlinux is a Debian "Derivative" which uses Debian's official repositories. Not to be confused with Ubuntu which is a Debian "Fork" and has it's own repositories. Something that we'd love to do, but we are a small team with few resources.
There are many derivatives and derivatives of derivatives, and each has it's own personal features. Each derivative also suffers with comments based on generalisation based on a lack of knowledge.
Linux Mint isn't just Ubuntu with a green desktop, PcLos isn't just Mandriva with a different theme, Dreamlinux isn't just Debian with a Mac-Style Desktop.
So what is different?
To start with, Dreamlinux has it's own custom kernel which always has any missing modules preinstalled for hardware such as wireless Nics. Currently Broadcom, ath5k, ath_pci, ath9k and the athloader for these drivers and firmware. Our kernel developer tinde always manages to keep it fast while maintaining a large hardware compatibility for most users.
This is where Dreamlinux is different from Debian as we don't stick to their "Free" policy, but choose to provide what the users need without getting into politics. There are other completely free and politically correct distros out there if you prefer that particular filosophy.
The Dreamlinux Installer
The Dreamlinux installer was also written by nelsongs and is the epitome of the k.i.s.s principle. It allows you to configure and install Dreamlinux from a single window without having to scroll through each step. It has been described as intuitive and fast, it has also been described as difficult to understand. I refer you to the Archlinux installer and the Ubuntu Ubiquity installer (both of which are very different just like the distros. It's a matter of taste and in my opinion common sense and the ability to read a howto guide
This installer is currently going through a major rehaul, where extra features are being added such as:
1. Pendrive (persistent and livepen) installer
2. Mkdistro Live Remaster (create a custom iso from your modified live session)
3. EasyRemaster (create a custom iso from a personalised installed Dreamlinux)
4. Eeepc installer
5. OEM iso creator
6. USB external harddrive installer
7. Install Dreamlinux from a downloaded iso to another partition without having to burn the iso to a CD.
8. Single Window or Multi-Window installer
Basically, the goal of Dreamlinux is to provide the tools for everybody (not just devs/programmers/hackers) to be able to create their own Dream distro, hence Dreamlinux.
Dreamlinux Specific Applications
DCP - The Dreamlinux Control Panel
A central Gui to configure your desktop. Network, Themes, Languages, Keyboard, Enable or Disable Compiz-Fusion,
Easy-Install The Dreamlinux Easy Installer Gui for applications which are not in the repos.
Google Earth, Google Gadgets, Picassa, Opera, Firefox (Debian uses Iceweasel), w32codecs, Handbrake.... the list goes on
Engage and AWN Animated Mac-Style Docks/Panels
Dreamlinux has a standalone Engage panel which as far as I know does not feature in any other non-enlightenment desktop. Xfce has it's own built in composite manager which allows for docs and transparent effects.
As soon as you enable Compiz-Fusion, Engage is closed down and AWN (Avant-Window-Navigator) automatically opens and replaces it.
The Dreamlinux Modular System - Flexiboost
I will describe this in basic laymen's terms, 1. because I have only just started using it since joining the dev-team, and 2. because it's nelsong's baby and he knows all the technical details far better than I.
It basically allows you to create standalone modules which can be added and removed from the distro without affecting the rest of the distro. Imagine you install Gnome, Kde, Xfce and decide to customise themes, icons, etc, and then decide to remove one of those Desktop environments, there will be a mess and probably some breakage.
With the modular system you just add a module which can be a complete, custom Desktop Environment, such as nelsongs and andrefelipe did when they added the Gnome desktop as an optional environment alongside the standard Xfce Desktop. The same was done for Open Office and various other modules which can be removed as easy as opening the iso and hitting the delete button with no advers affects on the rest of the distro, it's no different from deleting a folder from your desktop.
There are also more modifications which steer the boot routine to favour the Dreamlinux customisations (modules), over the standard Debian components which is why even after upgrading, the Desktop themes, icons, scripts do not get replaced or overwritten.
As you see, this pretty Debian with the Mac-Style desktop has a whole lot more going on under the hood than the average Linux user will notice. The same goes for Linux Mint, PcLos, Ubuntu and host of other derivatives, which is what I mentioned earlier.
There is more, but I think i've bored you enough Lol!
I hope that provided a little insight into what Dreamlinux is.
PS: Later i'll link to some screenshots, but it's dinner time now