that they are confined to browser-related and HTML-related tasks.
features that would be required for standalone
capabilities, except for the ability to format and display
HTML (which, however, does include images, tables, frames,
forms, fonts, and other user-interface elements).
allow the reading or writing of files. Obviously, you
wouldn't want to allow an untrusted program from any random
web site to run on your computer and rearrange your files!
kind, except--an important exception!--that it can
cause a web browser to download the contents of arbitrary
multithreading capabilities, except whatever comes
implicitly from the web browser's internal use of threads.