If you mean an "Operating System" upgrade then yes, but only up to a point. Depending on the size of the Processor the computer has you can upgrade up to 10.5 Leopard.
Snow Leopard, 10.6 is only for the Intel processor Macs.
The iBook G4 running Mac OS X 10.4.11 can be updated to Mac OS X 10.5 Leopard, which is the last officially supported operating system for that model. However, to upgrade to Leopard, you will need a compatible installation disc. Beyond that, while some users have experimented with unofficial methods or third-party software, the hardware limitations typically prevent effective upgrades to newer versions of macOS.
You will need to purchase a 10.4 (Tiger) disc to upgrade a Mac from 10.2.8.
128mb is pretty low, but if your ibook runs on mac OS 9, then it is not that bad.
That's correct, it will upgrade your video memory and not your system memory.
Mac OS X 10.4 (Tiger) can be installed on an iBook Dual USB (G3 processor) by inserting the installation disc and double clicking the Install icon.
An operating system is the software that runs your machine such as windows / linux / mac. So if you were to upgrade it you are simply upgrading to a newer version
Mac OS X 10.3.9 is nearly five years old (which is a long time in computer operating system years) the current version of Mac OS X is 10.5.7. The minimum requirement for the latest version of the Safari browser is 10.4.11. To update your browser you will need to update your version of Mac OS X. Mac OS X 10.5 (Leopard) will work on an iBook G4.
An iBook G3 Clamshell needs to be running Mac OS X 10.3.4 (or later) for iLife '05 to operate. Depending on the particular version of Clamshell there may be problems with the amount of hard disc space available for the iLife applications.
This will depend on the specs of the Mac mini in question but in general, yes.
No because the Mac App Store requires Mac OS X 10.6.6 which is not supported on the old G3/G4 iBooks.
I do not think that you can because it just wont let you do that.
Yes you can run Mac OS X on a iBook G3. You would not be able to run Leopard but you can run previous versions of OSX. 10.4 requires 256megs of RAM and 10.3 and earlier require 128megs of RAM or more. Though it will run with this amount of RAM, I would recomend getting as much ram as possible in your iBook because it will help alot on basic OS X functions. I did the same thing with a lower ended iMac G3 and when I upgraded the ram to 512megs instead of 256megs it ran quite a bit faster.