First let me say that building images from the Bottom Up in a pristine work environment is always a great option. It is my belief that many distributions, including Debian, build their officially released images in this manner.
However, for the average user who probably only wants a few minor adjustments to an officially released live Debian image they may be overwhelmed by one or more of the following:
The user does not build images on a regular basis and not sure where to start.
The user has little or no knowledge on the setup of a truly pristine build environment.
The user is overwhelmed with the tools and tool lexicon.
The user is confused as to why build attempts are failing.
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Hence the user's quest for a custom live Debian image may never be achieved.
So why not provide options for the user to reach their desired goal of creating a custom live Debian image. Top Down Remastering is a very viable option allowing users to create custom images. Furthermore these custom images can be based on official live Debian images.
Why are official live Debian images mentioned frequently?
There are many advantages of Top Down Remastering with official live Debian images. Below are just a few (not an exhaustive list) reasons why official images are preferred:
Official images are created by a talented team of creators.
Official images are pristine images.
Official images are production ready.
Official images offer a stable point in time reference to remaster with.
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Why the name SquashFS.net?
One primary reason is that squashfs filesystem is a key component of live cd's created by many popular Linux distributions.