An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is an essential component of the system software in a computer system. Application programs usually require an operating system to function.

Q.#1: Based on the comment posted 17 hours ago by 'Calvetti' if I'm reading it correctly I can upgrade to Leopard. But am I reading it right? Apparently my system does not have an Intel processor. I have an iMac G5 (2004?) 1.8 GHz PowerPC G5 currently running 10.4.11. If there is a disk to upgrade 'my' system could you please supply the url?

Mac OS X 10.7 (Lion) and above: Java is not pre-installed with Mac OS X versions 10.7 and above. To get the latest Java from Oracle, you will need Mac OS X 10.7.3 and above. Mac OS X 10.6 and below: Apple's Java comes pre-installed with your Mac OS.

Sametime for mac download. I have a Power Mac G5 Dual 1.8 with 3.5GB of ram running 10.5.8 The system feels so slow though.:( Taking in mind that this was a beast back then, which would be the best OS X version I could i.

I've only located the 'Box Set' on the Apple site, but the requirements indicate Intel. Q#2: Will I loose any files? Q#3: If I can and do upgrade will all my software still run or do I have to upgrade all of that too? Ill, photoshop, flash, dreamweaver, word, excel, powerpoint etc.

This whole quest started when I wanted to get a camera for 'Skype' and the Intuit 'Quickbooks' (for Mac). First, a giant thank you to you all. I think I get it - although very confusing because you're all debating the facts.

From what I've learned thru the muck of conflicting info, is that I need to purchase the full-install version of Mac OS X 10.5 Leopard. So the Answer to my Q#1 was answered. Let's explore my Q#2. Will I loose files?

I managed to find an Auth. Mac Tech locally, but the house call is pricey - he did indicate he would back-up everything before hand and do a diagnostic. Then the sales pitch of course. If I do this MYSELF. Do I need to back up my entire system and all my files? I run two businesses out of my home and my files are ultra important!