The major problem faced by 64-bit Linux users is getting Flash Player to work properly on the platform. With the latest version of Ubuntu, it installs the 32-bit release of Adobe Flash Player along with the necessary 32-bit libraries so it can work.
However, using 32-bit Flash is sometimes buggy (when it is working). What about a 64-bit version of Flash Player?
Gnash, the free (libre) alternative is not enough mature to work on all web sites. But Adobe is currently working on a 64-bit version of its player. It is now available in the labs for download. This is still a beta, so using this plug-in could make your browser unstable (also see warning at the end of this post).
Before installing it, you should remove any previous installation of Adobe Flash Player, you can use Synaptic (System -> Administration) for this purpose.
The downloaded file has the extension .tar.gz, it is a compression format like ZIP. You can double-click on it and extract the file (libflashplayer.so) to your home directory, or use the command line: “
$ tar zxf flashplayer11_rc1_install_lin_64_090611.tar.gz“. Now, you need to copy the extracted file to a system directory, close all internet browsers before doing so. It is assumed that the extracted file is in your home directory.
$ sudo cp $HOME/libflashplayer.so /usr/lib/mozilla/plugins/
You can now launch Firefox or Chromium on your 64-bit system and watch Flash media content. My own experience is a more stable system! But do not forget, Flash is not a free software.
Updated 2010-06-08: Adobe issued a security warning for all Flash players (all platforms) covering 10.0.45.2 and earlier release. Which most probably means that it includes the 64bit version as well (this is not confirmed). The only safe version (recommended by Adobe itself) at the time of writing is Flash 10.1 RC which is sadly 32bit-only.
Updated 2010-09-16: Adobe released yesterday a new preview of its 64bit capable Flash Player. Links in this article have subsequently been updated.
Updated 2011-08-13: Adobe released a second beta of Flash Player 11 which as 32bit and 64bit implementation. This release includes also an Adobe Flash system preference. Just uncompress the .tar.gz file in a temporary directory and copy the uncompressed usr folder to your root ‘/’ directory.
Updated 2011-10-01: Updated for the first release candidate of Flash Player 11.