You don't have to download it; all browsers have support for it built in. You have to download Java, which is something completely different.
Disabling Javascript (which is done in your browser's options menu) will affect your ability to open folders and notes/hottips.
Lost in Space
I think that 99% of websites on the Internet use Javascript, or at least scripting of some kind. Blocking it just makes for headaches. As was already said, Javascript is not the same thing as Java.
edited 22nd Mar '13 8:50:39 AM by Fighteer
"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"
World's Toughest Milkman
The Lynx browser is a text-only browser, often used by the blind in combination with a screen reader. It does not have javascript. Period.
And "99% of the web" is a serious exaggeration. Lots of the web uses javascript, but the sites that actually require it are far fewer. But yes, trying to get by completely without javascript is going to greatly limit your ability to access the web.
I recommend trying Links
v2, which is very similar to Lynx, but does apparently support some basic javascript. Most former Lynx fans I know of have switched to Links.
A friend of mine suddenly can't read TV tropes anymore because he doesn't have javascript - nor does he have any plans of ever getting javascript. Is the site simply off-limits to him now?
EDIT: He uses Lynx web browser, which does not support javascript (or flash).
edited 22nd Mar '13 8:52:42 AM by dearmissbea