The Adobe Type 1 fonts, previously known on CTAN archives as the
"bluesky" fonts, are now distributed as part of the AMS fonts
distribution, at CTAN:fonts/amsfonts

The fonts remain free: all Type 1 fonts in the AMS fonts collection
are released under the SIL Open Font Licence (OFL).

The fonts are currently the intellectual property of the AMS, though
they were developed by Y & Y Inc., and Blue Sky Research, who jointly
donated the fonts to the AMS, in cooperation with a consortium of
scientific publishers.

The fonts' original name arose because Blue Sky Research originally
submitted the fonts to CTAN; there was no other significance to the
name.

The CTAN Team