Why split modules to this name spaces? I would prefer to have just module 'purchase' instead of 'purchase_simple' and 'sale' instead of 'sale_simple'.

To be able to install purchase without stock or purchase without account.

This I understand. But Iam talking about names :-) sales|purchase simple are reduced modules sales|purchase from status quo? So why not just let the old name for the simpler modules? Or are purchase_stock, purchase_account not depending in purchase_simple?

Because it will not work for migration. And we prefer to have sale and purchase modules with complete features.

Havn't understand clearly. 1. sale_simple and purchase_simple are additional to sale and purchase modules? 2. sale_stock, sale_account both depends on sale module? 3. purchase_stock, purchase_account both depends on purchase module?

1. No they are the minimal base we can perhaps named it sale_base 2. No it is sale that will depend on sale_stock, sale_account and sale_simple/base 3. as 2.

1. Sale_base is a good name.

2. I am understanding more and more: It seems dependency tree will become like this, which would be ok.

+---sale_base
|   +---sale_stock
|   +---sale_account
|       +---sale

dito for purchase