The Yahoo! Desktop Widgets Gallery Website was discontinued on April 11, 2012.
It is believed that the Mac OS X and Windows versions of the Widget Engine itself will continue to be available here:
N.B. The Widget Engine runs on OS X versions up to and including 10.10.5 (Yosemite).
It does not run correctly on OS X 10.11 (El Capitan).
On Windows, the Widget Engine is known to run correctly on Windows XP and versions up to Windows 8.1.
Friday, October 9, 2015.