The Center for Neighborhood Technology invents and implements "new tools and methods that create livable urban communities for everyone." The CNT website contains links to several planning tools and provides a listserv.
The Community Problem Solving Project @ MIT offers free access to a group of Strategy Tools that can "help you approach issues and work with other stakeholders more effectively" and a group of Program Tools that help you respond to "specific, substantive problems by learning what works and what doesn’t in a given area."
The Tools Database offers a list of over sixty tools available for all aspects of land use planning and community participation.
The Smart Communities Network lists several planning tools on this page, with links to the tools’ websites.