This week's guests are on the frontlines of making cities sustainable with their work on housing, mixed use development and Main Streets.

Jonathan Rose has been called the father of the green affordable housing movement. His projects in the South Bronx and in Harlem are showing how green buildings ought to be for everyone. The national real estate firm he founded, , collaborates with cities, towns, and nonprofits nationwide to develop projects that are both green and socially responsible. Its mission is to repair the fabric of communities.

Brian Goodman is renewing Boston's neighborhood commercial districts through its Main Street program, demonstrating that old does not necessarily mean disposable. Brian manages Mainstreets WiFi and Boston Community Change and he has been a Peace Corps volunteer in Bulgaria, an entrepreneur, and an MBA student at Babson College.

We'll talk to Jonathan Rose and Brian Goodman this week on Smart City.