Hot damn. After all this time, Adobe released a 64 bit Flash plugin for Linux about a week ago, and while it’s still alpha, it seems to actually work. So far, YouTube videos play fine and the Daily Kos Electoral Scoreboard works better under the 64 bit plugin than it did under the 32 bit plugin running under nspluginwrapper. Time may show that it’s still unstable, but at least npviewer.bin isn’t sitting there sucking up CPU and memory now. (Firefox, of course, is still taking up a ridiculous amount of memory.)
Installation was surprisingly painless. All you have to do is shut down Firefox, remove the existing Flash plugin (with Ubuntu, apt-get purge flashplugin-nonfree nspluginwrapper, your distro will vary), make sure there aren’t any extra references to the old flash plugin laying around (I found dead links in /usr/lib/firefox/plugins/npwrapper.libflashplayer.so,
/usr/lib/mozilla/plugins/npwrapper.libflashplayer.so – locate libflashplayer will find them for you so you can delete them), and then install the new Flash player. The tarball from Adobe just contains libflashplayer.so. Untar it, copy libflashplayer.so to /usr/lib/mozilla/plugins, and then make links from /usr/lib/mozilla/plugins/libflashplayer.so to /usr/lib/iceweasel/plugins/libflashplayer.so, /usr/lib/firefox/plugins/libflashplayer.so and /usr/lib/xulrunner-addons/plugins/libflashplayer.so.
Once that’s done, fire Firefox back up, type about:plugins in your address bar, and you should see libflashplayer.so listed as handling Shockwave Flash. More time is needed to see how this new 64 bit plugin works on the long haul, but if it only reduces the bloat and CPU that was used by npviewer.bin, that’s good enough for me. If it also doesn’t segfault constantly for no apparent reason, that’ll be even better.