Canonical opened a debate on wether or not Ubuntu will switch to a rolling release model. What does rolling release model actually mean? Will there be a 13.04 release?
Rolling Release means that there is no definite release date. The only quality assurance that will be done is that maybe some kind of snapshot is defined.
If you look at debian, you find both models.
- stable is an ordinary release branch.
- testing is the development branch. It is renamed to stable if it gets released.
- unstable is a rolling release branch.
13.04 / raring will be released as planned.
Rolling release means that the software and the operating system get not only software updates that fix bugs and security related problems, but also get upgrades with new features added to the software stack.
In the current model, once Ubuntu gets a new release, the software that gets bundled are "feature frozen." That means that any software update through Update Manager gets only fixes (bugs and security). For example, if you have Libreoffice in Ubuntu 12.04, if you want the latest release, you would:
- Wait for backports
- Add an external PPA
- Or, upgrade to Ubuntu 12.10
In contrast, a rolling release model includes not only fixes but also the latest versions of software. This means that you wouldn't need external PPAs because Update Manager would always bring in the latest versions. That also includes parts of the operating system (kernel, drivers, libraries etc.)
Note that there has only been talk about this, but this has not actually happened. In fact, Mark Shuttleworth seems quite opposed to the rolling release model.
@Suman is on the money here, but not mentioning a critical point. @H.-DirkSchmitt is completely wrong.
The arguably most attractive part of a rolling release is the fact that there's never going to be any active upgrade on your part. Such as getting 13.10 to upgrade your 13.04 system.
All upgrades are performed continuously, there is no such thing as a "release" (like Precise, Quantal, Raring, Saucy), although a rolling distribution may simultaneously be the foundation for a regular release cycle (such as with Debian).
Think of it as Google Chrome-style updates for your OS.