Thanks Lawrence,

I have already a zope 2.13.7 installation following the instructions and using virtualenv. This seems to be an alternative to the buildout system explained in those links.

There are several options in the add-ons page and I don't feel confident it really applies to my case:

1) what is the ZSQLMethods package in pypi? http://pypi.python.org/pypi/Products.ZSQLMethods/2.13.4. It's a zip with some "egg-info" stuff in there but it is not clear that it really is an egg (no .egg extension)

2) is Buildout compatible with virtualenv? The option to install an Egg without Buildout is not recommended over there.

Fernando