no
Apple wanted to be the software, and hardware company. That way Mac OS X is built for the Mac computers.
Mac OS X is an operative system which means that it is a piece of software and not hardware. Software don't have measurable dimensions.
No
There is an older version of ClamXAV available (See links below) for Mac OS X 10.3 but as there are no viruses that attack Mac OS X anti virus software is superfluous.
The operating systems that are compatible with Adobe software include Windows 7, Windows 8, Mac OS X, Mac OS X Snow Leopard and Mac OS X Mountain Lion.
Software written for Mac OS X will only work on a Mac running Mac OS X it will not work with other operating systems such as Windows.
Omnigaffle is a charting software, similar to Microsoft Visio. Omnigaffle is compatible with Apple devices: Mac OS X Leopard, Mac OS X Snow Leopard, Mac OS X Lion and iOS (iPad).
There are several emulators to run other systems software on Windows, but there is nothing decent (as in working reliably with any software) for running Mac OS X software on Windows.
Mac OS X is supplied on a DVD with every new Mac. Upgrades to new versions of Mac OS X can be purchased from any retailer that stocks Apple software such as Amazon.
Click on the Apple menu in the top left corner and select About This Mac. This will open a window which will give the version of Mac OS X you are running. From the Apple menu select Software Update... which will check if there are any updates available for the Mac.
Updating to the latest version of Mac OS X will provide you with the latest printer software. HP keeps a selection of software for various versions of Mac OS X. (See links below)
The Mac OS X Tiger install DVD is the DVD that allows you to install 10.4 software onto your Mac. 10.4 is Tiger, and so it is called Mac OS X Tiger.