Debian is a GNU/Linux distribution. The name comes from the founder of the project, Ian Murdock, and his wife, Debra. Hence "Deb" and "Ian".

If you use Debian, you tend to love Debian. Why?

It's not controlled by a corporate entity.
Huge package archive
Debian packages over 11,000 pieces of software. You can install almost anything by just typing apt-get install package, with package dependencies handled for you. No more rabbiting around the internet for an RPM that might do what you want it to do!
Runs on lots of platforms
i386, AMD64, Motorola 68k, Alpha, Sparc, PowerPC, ARM, MIPS, HP PA-RISC, IA64 (Itanium) and S390.
Incredibly easy to maintain
apt-get upgrade every night and you'll be running the latest versions of everything.
Very true to Linux
Some purists dont like RedHat's directory structures. It's also pragmatic and ideological; what you know as Debian today is Debian GNU/Linux, and they are also looking at Debian GNU/HURD.

Often imitated, never beaten.

There are some reasons not to like Debian, the most obvious of which is that the "stable" distribution, while historically very stable, achieves this by being up to three years 'out of date'. Ubuntu, a derivative of Debian, addresses this by having regular (six-monthly) release cycles. Also, Debian has a mentality of "we have official packages for everything", meaning that $new_thing has to be uploaded into the repository before you can get it. However, more people are packaging things in third party repositories that you can add to your AptSourcesList, and you can always install things from source.

Read about the different FlavoursOfDebian.

Packaging in Debian

The Debian PackageManagement format is .deb. See DebianPackaging on how to create these, or DebianPackageTools for how to use dpkg(8)/APT/other programs that install .deb packages.

Acquiring Debian

See NewZealandLinuxMirrors for places in NewZealand to get Debs/ISOs.

Learn more

There are a LOT of great Debian web pages on the internet. Here are but a few...

Part of CategoryDistribution and CategoryDebian