What's the difference between flashplugin-installer and adobe-flashplugin?

I usually installed flashplugin-installer and by chance noticed that in the partner repository the Flash entry says it's not installed. It also says the package flashplugin-installer will be removed if I install the package from the partner repository named adobe-flashplugin. I've read this answer.

Does flashplugin-installer download Flash from Adobe as opposed to adobe-flashplugin available in the Partners repo? If not, how do they differ?

I've just downloaded both packages to inspect them, the process for comparing the packages can be found on the bottom.

adobe-flashplugin

It contains the Flash player library and configures itself as default for Internet browsers. It was only available for 32-bit systems, but since October 2011 a 64-bit version is available too for Ubuntu Lucid and later. This can be installed from the partner repository, see also How do I enable the "partner" repository?

flashplugin-installer

It extracts the 32-bit Flash player library from the adobe-flashplugin package (which is retrieved from http://archive.canonical.com/) and configures itself as default for Internet browsers. Additionally, it installs a 32-bit compatibility layer for 64-bit systems.

Conclusion

There is no change in the installed Flash player for 32-bit systems. For 64-bit systems, flashplugin-installer installs the 32-bit version of Flash and a related compatibility library which may be slower and less stable. I would recommend using the native 64-bit library instead (adobe-flashplugin).

Analysis

adobe-flashplugin was found in http://archive.canonical.com/pool/partner/a/adobe-flashplugin/?C=M;O=D (I haven't enabled the partner repository):

wget http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_10.3.181.26-0natty1_i386.deb

flashplugin-installer can be downloaded using apt-get download flashplugin-installer. For comparison, I downloaded the 32-bit package from http://packages.ubuntu.com/natty/i386/flashplugin-installer/download.

Programs used:

• dpkg-deb --control package_version.deb target-dir - extracts the control files (e.g. post-installation scripts) to directory target-dir
• dpkg -x package_version.deb target-dir - extracts the contents of the package to target-dir
• dpkg --contents package_version.deb - shows the contents of the package
• diff -Nur one two - compare directories one and two The postinst scripts were the most interesting as it makes the only difference between the packages.