OG Blueprints will never be _directly_ ported to D6 - when the time is right, it will be rewritten as a core part of CTools/Panels.
Organic Groups Blueprints is a system for creating and managing 'bundles' of 'blueprints' that are attached as OG panels to organic groups. The module is constructed on Panels2 and Organic Groups, and Organic Groups Panels (which is part of the normal OG package). Even if you're already familiar with those modules, OG Blueprints uses some new jargon that you'll need to learn. Because blueprints & bundles are a pretty abstract idea, I've included both technical and metaphorical explanations:
See README.txt for the technical overview.
- Panels & Displays: Not new, but important. Displays can be thought of as page layouts that are composed of rows/columns/regions, each of which is itself a 'Panel'. Each Panel holds a number of Panes; panes can be edited and filled with all sorts of content via the Panels GUI.
- Groups (OG): Also not new and pretty self-explanatory. Groups are just collections of people that exist because those people are considered members; there's no inherent form or shape to groups. So, bear with me through a metaphor: imagine groups as a vat of liquid wax that can be shaped any number of different ways.
- OG Panels: Specialized panels. They're just like normal panels when it comes to adding content and setting up layout. However, unlike normal panels, OG Panels can only exist if they're attached to a group. In terms of the metaphor, they can give form - think "wax sculpture" - to groups. Panels are the arms, legs, and torso of our sculpture, but they're nothing without the wax.
- Blueprints: If OG Panels are arms and legs, then Blueprints are molds of arms and legs. Pour the group-wax into a mold, and you get a nice wax body part.
- Bundles: Bundles are sets of these molds that together can form a mold for an entire wax sculpture.
Rephrasing the initial definition, OG Panels lets you give shape and form to individual groups. OG Blueprints lets you open a wax group-sculpture factory with you and your buddies: you can create molds (Blueprints) of all kinds, shapes, and sizes, then string them all together into Bundles. You can either have one mold that you use for all the groups on your site, or one mold per type of group. Whenever a user on your site decides to add a new group, OG Blueprints grabs the corresponding Bundle, fills it up with group wax, and presents a fully-built wax group sculpture. They're then free to add, modify, and remove parts of the sculpture as much as the OG Panels permissions allow them to.
NOTE: This module is a re-named, almost completely re-done version of OG Collections. It is considerably more stable, but is still an alpha - be warned!
Also - at this point, there isn't really much of an external API that other module developers would be interested in implementing. However, I've got doxygen documentation for og_blueprints that's updated every 24 hours, so if you're wanting to dive in and learn about how this module ticks, have a gander at http://doxy.samboyer.org/og_blueprints/.