You don't need to worry: Java and Javscript are entirely different things. To quote an answer on Stack Overflow:
timestamps of posts refreshing themselves every minute
clicking a link or an image to bring up a box, like the question mark above the answer editing area to bring up Help
live preview of question/answer as you edit
notifications that a new question was asked or the ...
I tested it now and it works fine for me.
I installed the current version of Chrome (Version 24.0.1312.52 m) and then the Tampermonkey extension, which is apperently like Greasemonkey for Firefox. It wasn't possible to install the script directly because of the "security" settings of Chrome.