  Millisecond pulsars (MSPs) are old neutron stars that spin hundreds of times
per second and appear to pulsate as their emission beams cross our line of
sight. To date, radio pulsations have been detected from all rotation-powered
MSPs. In an attempt to discover radio-quiet gamma-ray MSPs, we used the
aggregated power from the computers of tens of thousands of volunteers
participating in the Einstein@Home distributed computing project to search for
pulsations from unidentified gamma-ray sources in Fermi Large Area Telescope
data. This survey discovered two isolated MSPs, one of which is the only known
rotation-powered MSP to remain undetected in radio observations. These
gamma-ray MSPs were discovered in completely blind searches without prior
constraints from other observations, raising hopes for detecting MSPs from a
predicted Galactic bulge population.
