Linked from
The 9 pages that link to Stereographic projection, each with the reason it gives.
AstrolabeRelated: Astrolabes use this projection to flatten the celestial sphere onto a plate.
Riemann sphereRelated: It identifies each finite complex number with a point on the sphere.
Unit sphereRelated: It translates most points of the unit sphere into planar coordinates.
3-sphereRelated: It gives a coordinate chart covering the 3-sphere except for one point.
Al-ʻIjliyyahRelated: It makes the rotating celestial map of a planispheric astrolabe possible.