How do I install an application by DEB file for a single user only?

Well dpkg won't help you as this isn't its design aim. It wants to be a root-owned sole census of packages installed on a system. The only thing that jumps to mind is just extracting the package and trying to place the files manually in the home dir. However this will only work for some things. Plenty of packages are split into chunks (executables or scripts in /usr/bin, libraries in /lib and other garb in /usr/share, etc) and these locations are hard-coded in by the build scripts. Thus if you try and pull in something like this into ~, it will break. You could spend hours unwinding the dependencies but you could be doing something useful with your time like finding the cure for cancer or absorbing some of the beauty in the world. You'd do much better just to grab a non-packaged version from whoever writes the software. Almost all free software is available in some form of compressed archive as source so grab that and just build it. You don't do the make install step. Your app is built, just put it where you want it.

I don't know too much about this subject, but it seems from the other answers that you may be able to install a package to another directory instead of / with dpkg, using the --root parameter, and then do a http://en.wikipedia.org/wiki/Chroot to the dir which the package was "installed" in (which can of course be a dir in the home directory of the user). To install a package for a user other than root, it might be possible to use the above process with http://freshmeat.net/projects/fakechroot/ instead of chroot. Disclaimer: I did not try this, and do not have much experience at the time of writing with dpkg or chroot, but from what I do know about these tools, this process just might work. Links which have information which may be useful for people who want to achieve the effect of chroot without root capabilities: http://lwn.net/Articles/281157/ page about read-only bind mounts (it seems that this can be useful even to people doing a "standard" chroot http://www.serverfault.com/questions/135599/ubuntu-can-non-root-user-run-process-in-chroot-jail/135714#135714 on http://www.serverfault.com http://lxc.sourceforge.net/ http://www.ibm.com/developerworks/linux/library/l-lxc-containers/ about Linux Containers http://manpages.debian.net/cgi-bin/man.cgi?query=fakechroot&apropos=0&sektion=0&manpath=Debian+6.0+squeeze&format=html&locale=en) Update I now have done a little bit with things which touch on this subject, and found out some more... Fragments (local environment building blocks): https://github.com/fakechroot/fakechroot/wiki - emulates chroot(1) http://wiki.debian.org/Debootstrap - Create another Debian file system hierarchy inside a directory http://fakeroot-ng.lingnu.com//http://fakeroot.alioth.debian.org/ - Can pretend to be root for some things http://www.emdebian.org/ - A debian variant which uses less space and http://wiki.debian.org/EmDebian/CrossDebootstrap#Generating_cross_images_as_non-root_user http://www.kernel.org/doc/Documentation/binfmt_misc.txt - Can run files, using their interpreters, as if they are native binaries; useful together with qemu-user for working with binaries (or in a (fake)chroot) of foreign architectures (http://git.qemu.org/?p=qemu.git;a=blob_plain;f=scripts/qemu-binfmt-conf.sh which comes with the QEMU source code automates this) http://wiki.qemu.org/download/qemu-doc.html#Linux-User-space-emulator - Can run binaries of other architectures; can be used with some of these tools when they do not support some processor architectures http://en.wikipedia.org/wiki/LwIP - A TCP/IP networking stack which can be run from user space Full (complete local environment providers): http://user-mode-linux.sourceforge.net/ - runs another linux system as a regular process/program http://www.qemu.org - Run a complete virtual computer https://github.com/cedric-vincent/PRoot - Provides functionalities of chroot(1), mount --bind, binfmt_misc, and running binaries from other architectures using qemu-user-space http://lwn.net/Articles/531114/#series_index - Allows to have full root inside a local environment, when using http://lwn.net/Articles/528078/, a feature that is available in Linux kernel versions 3.8 and after. Summary: By emulating, or actually having, root privileges locally, DEB packages can be installed for a local environment.

You can probably use the --root option of dpkg to install to another directory. But will probably run into problems if the application looks for stuff in fixed places like /etc. In short, I don't think there is an easy way.

You could change the executable file's ownership so that only one user would be able to run it. Then, if needed, you can remove the application from the menus of other users.

Doubtful. The deb's are mainly archives that get extracted to the root of your filesystem when installed (plus some config). If you wanted to install them just for one user, you would need to somehow install them to /home/user folder. Even if you did so, they wouldn't work, as f.e. application binaries won't land in /usr/bin (or sth similar), and system will not find them if you'll try to launch them. Similarly libraries etc. would be useless, as the system wouldn't know there are somewhere in the /home. You could try the brute-force approach, and adjust the PATH variable to point to wherever you extracted the files from the deb archive, but that would be not only VERY insecure, but might cause may compatibility problems (f.e. menu entries wouldn't work, as GNOME extects the .desktop files to be in /usr/share/applications). Moreover, if you installed a package just for some users, it might cause crazy dependency problems, if any other user installed package that conflicts with another one you have had installed just for yourself - and possibly tons of other package management related issues would appear. All these troubles make it extremely difficult to manage packages separately for users, so it seems it's not possible to install them just for one user, because the idea behind the .debs disallows that.