Will the LS4 version be finally stable and is there a final estimate of when it will be.

As I can see for Yii 1.1, support is valid until the end of 2021
www.yiiframework.com/release-cycle

I don't know what version of Yii the LS4 is based on, but I can see the LS5 is already mentioned. If the LS4 version is dropped in favor of LS5, will it be backwards compatible?

And what if the LS4 / LS5 are still not stable enough. And LS3 will lose Yii 1.1 support? This is important from the point of view of software implementation for customers requiring a high level of security and application stability.

You posted your question in the LimeStore section. Perhaps someone can move this thread to the development section.

While your're waiting for an official statement by LimeSurvey GmbH, there might be more questions around the future of LimeSurvey by others.

LimeSurvey version 5 will be not much different than LimeSurvey 4. It's more about technical debts and requirements of dependencies like Twig and PHP.

We will see new requirements. The change is already happening in LS4.
E.g. PHP 7.x
github.com/LimeSurvey/LimeSurvey/commit/...a1535b3d8ad322f95d33

PHP 8 is around the corner. So Yii, Twig etc. will all need to be checked, modified or upgraded, to still play all together.

In my view LimeSurvey 5 will contain no main feature update in comparison to LimeSurvey 4, but also not break your current themes or surveys. But internally things will change and since LimeSurvey follows the semantic versioning concept, they will have to change to version 5.

But that is only my educated guess.

Moving to Yii 2 is needed,
We talk of this , but we need before to fix internal old issue and make a lot of separation af all code.
Hope we can before end of 2021 …

Moved to future feature ?

Depends on how you define "stable". There are at least two ways we use internally:

* No risk of data loss during usage (we think LS4 is there now)
* Less than 30 bug reports per month (LS4 is there, but needs more time still)

30 bugs might sound much, but LS is a big system, and most bugs are not blocking.

LimeSurvey 5 is needed for the Twig library, and to support PHP 8. That's the only reason.

LS3 support will last 2021 out. I believe LS5 will be as stable as LS3 within some months.

LS3 has around 20 bugs reported per month since 2020.

As for me, stable, i.e. safe in production, with long-term support (LTS).

Because currently, even on the official website, it is not recommended in a production environment, and if not, for some reasons?

Because I can use 4.x privately. However, when it comes to the client environment (for corporations), it has strict security requirements. I think that even with the purchased support, switching to version 4.x is not recommended at the moment? Even though the number of reported problems is comparable to version 3.x.