Doesn’t apt / dpkg / yum / pacman etc. does what UBOS Gears does already?

No. They all manage software Packages. They do not manage full configurations of the code in those Packages into running web Apps.

Take WordPress as an example. If you install a WordPress Package with one of the package managers above, it will dump all the WordPress code on your drive, but it is left to you to create a database and edit the Apache virtual host configuration. That is in spite of the fact that installing WordPress is much simpler than installing most web applications where you often also need to install (or even compile) additional dependencies, and sometimes even get additional services to run.

If you want to run the same application more than once on the same machine (for example, at different virtual hosts), package managers are not able to help at all. Certainly they also don’t help with backups, restores, SSL/TLS configuration and many other administration tasks that UBOS Gears helps automate.

P.S. We build on top of pacman (the Arch Linux package manager) and each UBOS package is a valid pacman package. ubos-admin invokes pacman somewhere in the middle of rather more functionality.