There are quite a few Debian rolling release distros available, but less common. Most of them are based on Debian unstable and Debian testing, but I've fond them surprisingly stable.
Though certain components like plasma desktop, Gnome 3 are somewhat troublesome.
Undoubtedly Debian and Debian derivatives are most popular GNU/Linux distribution. Though Debian stable versions are rock solid, they all lacks latest softwares in their repository. It's highly appreciated for servers, but a bit tough as a regular desktop OS.
So Just install one these debian rolling release, simply update to latest version and enjoy latest software with Debian goodness.
Let's explore them one by one,
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One of the most actively maintained Debian beased rolling release distro, focused to be a desktop OS, based on Debian unstable, currently Sid. Though it's a unstable branch, I've never seen any broken package.
Siduction provides many packages not currently available in the official Debian repository. Pre packaged ISO files are availeble for x86 (32 bit) and x86_64 (64 bit) architecture, with all major desktop environments like KDE, Cinnamon, Gnome, LXQt, XFCE and many.
Official website: http://forum.siduction.org
Both SolydX and SolydK are available as ISO files for x86_64 platform, it also provides OS images for Raspberry-Pi 2 with XFCE desktop.
SolydXK team maintains a quarterly package update schedule, almost perfect timing. Every packages are expected to be stable enough for day by day use.
Official website: https://solydxk.com
3. Linux Mint Debian Edition
LMDE team timely releases ISO files for 32bit and 64 bit architecture with two desktop environments, Cinnamon and MATE. It also has it's own package repository and maintained actively.
Official website: http://linuxmint.com
SparkyLinux is Debian testing based rolling release distro from Poland. The good thing is that it's well maintained and with it's own repository. It's slowly gaining popularity among Debian users.
Many types of SparkyLinux ISO files are available for download, from minimal CLI only editions to huge 4GB "GameOver" editions.
Official website: http://sparkylinux.org/
New Aptosid ISO files are released rarely, but the package repository is maintained actively. It's available in two ISO files, featuring XFCE and KDE desktop respectively.
Official website: http://aptosid.com
6. Kali Linux rolling edition
Kali Linux needs no further introduction, ISO files are available for x86 and x86_64 architecture featuring a Gnome 3 desktop.
Official Website: https://www.kali.org
This one is of Italian origin based on Debian Sid, with their own Openbox based desktop environment, vera .
Simsplice team also maintains their own "unstable" repository for their Current version which is rolling release.
Know more about Simsplice > http://semplice-linux.org/discover
antiX ISO files are released frequently, available for both x86 and x86_64 architecture. It maintains a true rolling release cycle and the package repository is also well maintained.
Official website: http://antix.mepis.org/index.php?title=Main_Page
There is a proposal of true Debian rolling release distribution named Debian CUT, but it didn't showed much activity since it's proposal in 2012.It's also possible to use Debian testing as rolling release, until they are frozen to be stable.
This list is pretty comprehensive, if you are using/know about some other actively maintained Debian based rolling release distro, please inform me, I'll add them to this list.
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