How do I install several versions of Opera in Ubuntu?

It is very easy actually. Multiple side by side installs are now supported by the new install script, via install suffixes. During install a (user selected) suffix can be appended to the name of the install files and directories, e.g. if I was to use the suffix 'snapshot' the Opera startup script would become '/usr/local/bin/opera-snapshot' (for a system install) and the shared resource directory would become /usr/local/share/opera-snapshot (other files and directories will also be renamed in a similar vein). Better yet this suffixed install would get its own shortcut in the desktop environment's application menu and would use '~/.opera-snapshot' for its profile settings rather than the main profile ('~/.opera').

Uninstalling Opera is now made easier due to the fact that an uninstall script is created during installation (by the tarball install script) and placed in '/usr/local/bin' (or '~/.local/bin' for a user install). The uninstall script is called 'uninstall-opera'. If side by side suffix installs are done, a unique uninstall script is created for each, e.g. 'uninstall-opera-snapshot'.

So basically you just need to use the tarball package rather than the .deb. Firstly download the appropriate package:

Opera 10.54 (6335) 32bit
Opera 10.54 (6335) 64bit

Assuming you use 32bit linux and downloaded this to your '~/Downloads' directory you could start a terminal window and install it as follows:

cd ~/Downloads
tar xf opera-10.54-6335.i386.linux.tar.bz2
opera-10.54-6335.i386.linux/install

During the install process you will be promted if you would like to use a suffix, choose something suitable like snapshot, test or perhaps the build number 6335. After installation is complete you may need to log in and out of your desktop environment before the suffix installed appears in your Applications menu under Gnome.

Originally posted by marcorion:

Um you really cannot. All *nix versions of Opera when installed run to ~/.opera to store configuration info.

This is no longer true. Suffixes allow for side by side installs. This functionality was introduced in the tarball install script for 10.5x.

Originally posted by RocknRolf:

cd /path to the folder/operaversion/
./opera

If you like you can avoid the initial cd and just issue:

/[path]/opera

This was fixed in 10.5x, so that cd'ing first is no longer needed.

Originally posted by lamarca:

testing opera under unix/linux, without changing your main profile settings.

Hmmm ... I should update that at some point to mention suffix installs. These are arguably the best way these days since you can have a unique profile for each install but also get desktop environment integration.