A matrix is a two-dimensional wizard. Really.

• A hierarchical wizard is a tree-type structure of categories with nodes that lead to "wizard pages".
• A sequential wizard is just a flat step-by-step sequence of "wizard pages".
• A matrix is a row-and-column grid of cells, each of which takes you to a "wizard page".

That's it!

How do I develop a workflow for creating an XSL ePortfolio template inside Sakai and OSP?

This is a two-step process. First you'll need to get your hands on the XML that you'll be creating your XSL for (you do this by creating a pass-through template so you'll have the resulting XML to work with) Second, you can develop the XSL and your XPATH expressions on your local computer with minimal fuss.

Short version:

http://collab.sakaiproject.org/

Long version:

If you're tinkering with Sakai or its Electronic Portfolio "Open Source Portfolio (OSP)" you might have questions -- or you might find yourself wanting to contribute back to the community (documentation, quality-assurance testing, project management, java or XML coding...)