I've always wondered, what are those dual-layered (bonus: sometimes they have a little <2mm hole, why is it there?) windows commercial jets put next to their seats made of?
Generally aircraft windows are made of what we colloquially call "plexiglass" of some kind (Lexan polycarbonate is common in light General Aviation aircraft, acrylic plastics are also used). This material is light, relatively strong (not shatter-proof, but it'll take a moderate beating) and has decent optical properties.
Bonus answer: The little hole serves a couple of purposes, but the biggie is pressure relief/equalization. This gets discussed over on airliners.net a lot and they've covered it pretty thoroughly.
Basically the hole ensures that the cabin pressure is pushing against the outer (primary, usually thicker) sheet of plexiglass, which is plug-wedged into the fuselage structure and can't go anywhere.
The small hole is there to provide ventilation and enable removal of moisture/condensation, but the hole is only in the thin protective screen on the inside. The much thicker actual window that holds the pressure is (hopefully) not punctured.
Most windows (Boeing) are a triple layer of plexiglas - Cabin air circulates between panes for defogging - Except the windows found on cargo doors (electrical heat instead) - Elasticity is the main reason why they are strong -
Windshields are different, must resist to bird strikes and be heated - One inch or more in thickness and special optical corrections - A windshield pane for a 727 was $10,000 in the 1980s...!
Note that some airplanes have two different Vmo - Because of windshield bird strike resistance - As an example, some Learjets - Vmo (low altitude where birds are) is 305 KIAS - Vmo (high altitude, above FL 140) is 358 KIAS -
I did fly as Learjet instructor in the early 1970s - I was told the windshields of the 24/25 were "birdproof" - Could resist a 4 lbs bird hitting the windshield at 350 mph - I wondered if it could resist a 350 lbs turkey at 4 mph...? ROFL -
One note also about a fire axe - If you wish to make a hole to escape, do not try windows - Windows are extremely resistant - It is better to use a fire axe against metal (fuselage skin) -
Look at UK-CAA airplanes and "cut here" frames on side of fuselages - Airfield firemen are knowledgeable about not trying to "break" windows - And would open fuselages within the "cut here" frame indications -