Billiards

Some (mostly on-line) resources

Some books:

Rational billiards:

Billiards in Triangles:

Billiards in Ellipses:

Outer billiards, dual billiards:

Billiards on hyperbolic plane:

Optics and mechanics:

Miscellanea:

Slides of some talks:

Some videos:

Some webpages: