No need to split hairs. But Fedora, Centos and Redhat all operate the same way. Wikipedia, which contains not nearly an exhaustive list of Debian-based distros turns up this:
Tails (operating system)
Ångström distribution
AntiX
Astra Linux
AV Linux
BackBox
Baltix
Bharat Operating System Solutions
Canaima (operating system)
Commodore OS
Corel Linux
CrunchBang Linux
Damn Small Linux
Debian Pure Blend
Debian-Med
Devuan
Dreamlinux
Dyson (operating system)
Emdebian Grip
Finnix
Debian GNU/kFreeBSD
GNewSense
GnuLinEx
Grml
Guadalinex
HandyLinux
Instant WebKiosk
Iskolinux
ISURU Linux
KaeilOS
Kali Linux
Kali Linux NetHunter Edition
Kanotix
Knoppix
Libranet
LiMux
Linspire
Linux Mint Debian Edition
LinuxBBQ
Loco Linux
Maemo
MEPIS
Mklivecd
Musix GNU+Linux
MX Linux
OpenZaurus
Pardus (operating system)
Parsix
Pixart
Progeny Linux Systems
Proxmox Virtual Environment
Reconstructor
Remastersys
Sacix
SalineOS
Skolelinux
SolydXK
SparkyLinux
SteamOS
Stormix
Sunwah Linux
Symphony OS
TurnKey Linux Virtual Appliance Library
Ubuntu (operating system)
Univention Corporate Server
UserLinux
USU (operating system)
VMmanager
Vyatta
VyOS
Webconverger
Wienux
Xandros
YunoHost

as Debian-based distros.

Ubuntu uses all the same Debian tools that Debian does, and mostly the same packages. Any Debian documentation can be applied directly to Ubuntu.

Debian wasn't first. But it is everything I previously stated now. WHY? Because it has a massive number of developers!

Other distros are equally usable, maybe even more so. But I'm not a distro evangelist. I simply state the facts as best I can.

My point was they don't "operate the same way" any more than all Debian based distros "operate the same way".

Having rpm packages or deb packages is just one facet of a distro and implying that the package manager makes them all the same is specious at best. My post wasn't splitting hairs but rather an attempt to correct FUD.

By the way there are other multiple other distros in the RPM family. This site shows multiple Fedora based distros and a separate list of RHEL based distros (which helps put the lie to the "operate the same way".
https://en.wikipedia.org/wiki/List_o..._distributions

Clearly you're a fan of Debian and it makes me wonder if you actually use these RPM based distros and if not what makes you think you can comment on how they operate.

Also as noted previously there are other distro families such as Slackware that you seem to want to ignore.

Debatable.

I'm surprised SELinux hasn't been mentioned. That's one of the bigger difference between Debian and Red Hat.
Slackware 1993
Debian 1993
Red Hat 1995

October 1994 for RedHat (distro name - one of the 2 companies that became RedHat was formed in 1993).

You're right that early versions of Debian were available between Aug and Dec of 1993.

P.S. One of the things I liked about Debian early on was it had been ported to non-intel platforms so I was able to run it on my HP PA-RISC workstation for years. They finally quit supporting that (not surprising given that HP quit making PA-RISC systems at the end of 2008). I think they do still have ports for SPARC and PowerPC (and probably Itanium which RedHat dropped a few years back).

http://DistroWatch.com/dwres.php?res...age-management (since DW wasn't mentioned yet here)
Also, the Search options at DW are interesting (for related research).