Best OS to use on an iMac G3?

Hey Mac users, I have a PowerMac G4 (400Mhz) with OSX 10.3 - it runs just fine for basic things (like the net & e-mail), but anything else & it is a bit sluggish.

I am looking to buy an iMac G3 for a relative who is totally new to computers;

I'm going to be buying her a cheap iMac (<£50) - Probably a Blue/Red
APPLE G3 iMAC 400 MHZ HDD LOADED - I will pop in it 512mb ram and 40gb Hard Drive.

But I was wondering, would OS9 or OSX be best on the system, she isn't going to be doing much more than e-mail/internet and word-processing?

What do you think?

I don't know much about the difference between G3 & G4 so I need your help.

Thanks.

The main problem with OS9 is older applications. Web Browsers that really are not up to date and will have a lot of problems on many pages on the net. I would stick with 10.3 if I were you as most new applications will run on it. I know it won't be overall as Snappy as OS9, but it will work so much better on the Web and be a lot more stable. You can install Tiger on that imac since the 400 had Firewire, but it might be a bit slower than Panther unless you turn off the Widgets and other stuff in Tiger. I have 10.3 on a 333Mhz iMac and except for the fact it is not really snappy, it's dead stable and useable for what you want your iMac for.

PS, I would stay away from 10.2 Jaguar as it's getting to the point that a lot of new applications will not even run under 10.2. Just thought I would point that out.

Yeah, OS 9 is obsolete and antiquated. It will have trouble with modern websites and applications. There is no support for it from Apple and no software updates for it.
Go with at least OS X 10.3 and if you can, put as much RAM in it as it will handle.

I would go with 10.3..

OS 9.2.2 will run faster, but as mentioned above it lacks many of the features and software that are basic to modern computing. The more important thing that it lacks by comparison with OSX is stability. I say go with 10.3. It is fully modern, and faster than both 10.2 and 10.4.