040000 tree f6c5f40ea00e72e9e0b2254ffd0ffbf60327b949	gregbook
040000 tree e685c78a153aebefc03a32d593efa415c1be991b	pngminus
040000 tree 79c432701cd6280e17fd2bf5c66118be5e797319	pngsuite
040000 tree ea957597f98f3105debf4f92e65ee1b5a2ee1625	visupng