[Python-3000] Python 3.0 Porting Strategies

["Martin v. Löwis"]

> For new code, however, there is an alternative strategy that doesn't 
> involve 2to3 at all, which is to write code in the "greatest common 
> subset" of 2.6 and 3.0.
> 
> As Lennart Regbro pointed out earlier, this common subset is actually 
> quite large (larger than Guido originally intended, I think), and you 
> can write some fairly substantial applications in it.

I think it's worth noting that the subset is large only for 3.0 and 2.6.
If you need to support 2.5 as well, the subset is significantly smaller;
and if you also want to support 2.4, the subset is again even smaller.

Regards,
Martin