Dark Sky Partners LLC is formed of principals with long involvement in and commitment to improving understanding of light pollution. DSP provides professional services for the measurement of sky glow, as well as predictions of the effects on sky glow of existing or proposed developments, community growth, and changes to outdoor lighting due to retrofits or lighting regulations. DSP also initiated and provides continued support for the EONS (Eyes on Night Skies) project, which monitors sky brightness in two photometric passbands at selected sites across the US.