PANTONE COLOR MANAGER Software is a robust desktop application that works in tandem with your favorite design software to ensure you always have the most up-to-date set of PANTONE Colors available at your fingertips.
Looks like it works with Adobe, QuarkXPress, and Corel. I emailed them on this, and they said if Inkscape can import libraries in Adobe format, it may be possible to save the libraries from PANTONE Color Manager and import them.
Seems like a useful tool . . .