Odoo initiialy build and come as tinyERP which use odoo framework.
than tinyERP was really bad crappy and useless product and higly slow. Owner had both domain tinyerp.com and odoo.com
than they changed name as openerp, but its also become populer as very slow product.
than again they changes polices and change name of product as odoo which was initially they known as "On Demand Open Object" framework. Around 2010 or 2012 owner already take over the domain name. but than no use it.
After community great efforts tinyerp upgraded and owner delete his own tweet for keeping it as pure open source he change license too.... than that odoo framework which convert to product and become ODOO as product which failed in big ERP markets. odoo apss know you know it more.
In case you want to know how framework build and hack the framework than use version 5 or version 6 code.
You can fork version 6 do reverse engineering and get the framework main back, than you case use your own idea and create own new product, but don't fork after 6.0 version.
Also I told you version 6.0 with smart way of server implemenation, fast in work too. We had already utilized it.
Odoo was framework of tinyerp,openerp,
evthan odoo become product.
Framework or ORM of odoo,
Its mainly focused with ORM + Default some pre-setup addons = framework of odoo.
than rest all modules loaded and control over it.
Enterprise odoo just had GUI different and rest all same, some of their private module can easily build in community version too, just find smart person in international developers market.
Since begining odoo is slowest product & most wired in polices or licenses.
In case just you want to sale one ready stuffs after adding few features, its good,
but not good in case you want to create own new product or brand.
Also because of it hangs only on postgresql database, so tight on transactional systems only.
Don't expect super speed like wordpress website or estores platforms very popular in market.
Never even compare django+mysql/mongodo system with odoo,
vast different django is super exterim fast & fast for complex product development.
odoo is stuck on their own rules and hangs on polices.
Expense on recovery of failuer on odoo is very much high,
Also official of odoo is too much costly.
As compare to launchpad now on github for community edition,
official not very much involved because their main focuse on Enterprise edition only.
Enterprise edition just UI little better else too slow...
odoo Community edition is free, expense few $$$ than you got nice look in community edition too.