OK, this is going to be really BASIC, but I bet a LOT of people have the same questions:
Does Foundation USE Rapid Weaver, or does RW USE Foundation?
Are “Stacks” compatible between RW and Foundation?
Is Foundation mostly for “advanced” users who are not happy with some of the limitations of RW?
I’ve used RW some, but I know there is a lot I can still learn to do with it. Should I continue investing time in RW, or, switch to Foundation and invest my time there?
RapidWeaver is the core that all you mention run under.
Stacks is a plugin(a type of page) for RapidWeaver.
Foundation and Foundry are sets of add-on stacks (need to Stacks Plugin) as well as a theme that have a lot of additional functions built-in.
You can have a stacks page on any RapidWeaver Theme. Most Foundation or Foundry Stacks will only run with their theme.
Foundry, Foundation, UiKIT, Source, Platform, and probably missing others are also referred to as “Frameworks” as they start with an empty page, but have everything you need to build a website included.
All of these would probably be considered more advanced stuff, not difficult but a learning curve.
Doug explained it pretty well… Foundation and the other mentioned frameworks basically give you a blank slate in which to design your website.
RapidWeaver supports themes and plugins from 3rd party developers.
If you want to get serious with building sites in RapidWeaver, you need the Stacks plugin from YourHead. this opens up and huge new eco-system of stack developers (myself included).
Foundation works with the Stacks plugin to give you the power to design your own theme/layouts.
Hopefully that helps you more than confuses you.
FYI, I am releasing the latest version of my Foundation stacks tomorrow! Stay tuned…