Can NetBSD/i386 run Firefox and Mozilla?
Firefox and Mozilla have been ported to run on NetBSD natively, and pre-built binary packages are available through the NetBSD packages collection (see www/mozilla and www/firefox). If you’d like to run binary-only plug-ins, such as Flash, you’ll need to use Linux emulation. There are pkgsrc packages for many plugins available already, eg multimedia/adobe-flash-plugin, that also know which dependencies they have, so if you pkg_add them you ought to be fine.