Candid (formerly The Foundation Center and Guidestar)
The Foundation Center has long been a leader in providing resources to the philanthropic community. In 2019, TFC merged with Guidestar, another leader in this area, to form Candid. Their site includes a search form that returns basic information about private foundation funders, as well as links to their 990s. They offer a number of other fee-based services for foundation researchers.
NOZA's Private Foundation Database
NOZA provides access to this database of 990-PF tax returns. This project was started several years ago by Grantsmart and contains publically-available data received from the IRS. To search NOZA's companion database containing more than 1,000,000 foundation grant records (also free), please visit www.nozasearch.com.