[Zope3-dev] Re: Zope 3.4.0a1 released

[Martijn Faassen]

Hey,

> Compatibility with Zope 2
> --------------------------
> 
> We continue to work on the transition from Zope 2 to Zope 3 by making
> Zope 2 use more and more of the Zope 3 packages. But we're not there
> yet. **You can't run Zope 2 applications in Zope 3.**

I just realized that this text could easily be misread to imply that we 
are working on making Zope 2 applications work in Zope 3 (we're just not 
there yet). That is not the case - we do not expect ever to have a 
version of Zope 3 that can run Zope 2 code.

I'd suggest a rewrite to say:

Compatibility with Zope 2
--------------------------

Zope 3 is not upwards compatible with Zope 2. This means you cannot run 
Zope 2 applications in Zope 3.

We continue to work on the transition from Zope 2 to Zope 3 by making 
Zope 2 use more and more of the Zope 3 infrastructure. This means that 
new code written in Zope 2 can benefit from Zope 3 technology. Also, 
with care, code can be written that works in both Zope 3 and Zope 2. 
This allows a Zope 2 application to slowly evolve towards Zope 3. 
Unchanged Zope 2 applications are never expected to work in Zope 3, however.