5
Basically, it's the same with every new version (this is the start of a new series of releases, the 2.2 series, after we had the 1.x and 2.0 series). Some new features have been added, so not all 2.2 modules will be backwards compatible. You will be hardpressed to find applications for the 64 bit operating systems to run on 16 bit OS's, for the same reasons. But, that would mean the old releases would have forward compatibility, and -aside from the Instant Video system on board of the Spaceball's mothership- this has not been invented yet
There will not be a 'compatibilty' list for X2.2, simply because there are a lot of modules out there that would need to be checked on all kinds of platforms under all kinds of circumstances. Too big a task.
However, there will be a document explaining the changes made to X2.2, where compatibility could be an issue. This means it will explain the proper use of the X2.2 API, especially where there have been changes compared with X2.0.x.
Great care has been taken to keep backwards compatibility with the XOOPS 2.0.x
API. This is an important distinction, because if a module has implemend the API incorrectly, then compatibility could be broken. But that's what the API is there for, and why XOOPS exists in the first place: extensible, modular, object oriented should make it possible to upgrade easily, if used correctly.
So now it's up to the module developers to check if they have used the API correctly, and to check whether the changes and additions made to the core and its API affect their modules. And those are the messages you see popping up here and there.
So, don't worry
Herko