We have just put up on our site a description of our capital model.  It talks about how we deploy our capital via grants, program-related investments, and our endowment to support positive social change.  We look at it as a continuum of different financial tools that are working in the same direction.  You can read about our approach here.  You can also read in more detail about our program-related investments, which are below-market loans and equity holdings that supplement/complement our grantmaking, here.