Please help us help you and fill where relevant:
Your LimeSurvey version: 5.6.10
Own server or LimeSurvey hosting: Own server
Survey theme/template:
==================
We would like to update Limesurvey and it has come to our attention that there's a 6.x version. (We're currently on 5.6.10).
This means there are now 3 versions supported by LS.
There's a 3.x, 5.x and a 6.x of which the 3.x is a LTS version.
We have three questions about this.
- Will 5.x become the LTS version eventually?
- Is the 6.x version a stable, production ready version or do we need to see that as a beta version?
- Is there a way to update from 5.x to 6.x through the comfort update? Seeing the PHP versions don't overlap and the comfort update won't touch the PHP version itself. The manual doesn't mention anything about updating from 5.x to 6.x, so it looks like we also need to update PHP in this step.

What do you guys recommend?

Disclaimer: This is no official information, only what I expect from experience or have heard and seen somewhere.

I think LS3 will be EOL soon, so I don't think we need to consider LS3 in your case, as you are already on LS5 anyway.

We have three questions about this.
- Will 5.x become the LTS version eventually?
- Is the 6.x version a stable, production ready version or do we need to see that as a beta version?

I wouldn't consider LS 6 as beta, but as it is still at the beginning of its life, there might be one or the other hickup. But from what I understand, there is little technical difference between LS5 and LS6, the differences are mainly in the layout of the backend. So I don't expect major issues with LS6 at this point.

- Is there a way to update from 5.x to 6.x through the comfort update?

Yes, you can update LS5 to LS6 via Comfort Update.

Seeing the PHP versions don't overlap and the comfort update won't touch the PHP version itself. The manual doesn't mention anything about updating from 5.x to 6.x, so it looks like we also need to update PHP in this step.

Having the correct PHP version on your server is your responsibility. As you said, Comfort Update doesn't touch PHP, it only offers a comfortable way to update your Limesurvey installation. The server underneath is your responsibility.

PHP Versions required for LS5 and LS6 do overlap ( www.limesurvey.org/manual/Installation_-_LimeSurvey_CE ):

PHP version requirements:
LS 6.x from PHP 7.4.x to 8.1.x
LS 5.x from PHP 7.2.5 to 8.0.x
LS 3.x from PHP 5.5.9 to 7.4.x

Both LS5 and LS6 seem work between PHP 7.4 and 8.0. So if your server runs anything between 7.4 and 8.0 you should be fine.

Hi,
Thank you for your reply! We do have a follow up question though. In your reply you said "Yes, you can update LS5 to LS6 via Comfort Update."
How do we do this? Only the most recent 5.x version is visible to us.

Yes, you can update LS5 to LS6 via Comfort Update.

I actually thought this was the case, but since learned that this is not possible yet. Sorry for the confusion.

Currently you can only update within LS5 or within LS6. At the moment, it is not possible to upgrade from LS5 to LS6.

If you are a paying customer of Comfort Update I would open a support ticket with Limesurvey GmbH (Go to Limesurvey.org and click on "Support"), so they are aware of this situation and that you (and probably others), would like to have the possibility to upgrade from LS5 to LS6 using Comfort Update.

www.limesurvey.org/support/contact