Since Windows 8 changes a lot of things like the user interface, many people are starting to consider the alternatives. But what are they?
First we have older versions of Windows, Windows 7, Windows Vista, Windows XP, Windows 2000, and so on. The thing is the farther back you go in Windows the less likely you are to run modern apps. XP, Vista, and 7 run most apps, but soon XP and Vista will be phased out by Microsoft support and then we have Windows 7. Some people need older versions of Windows to run legacy software and in the case of video games and 3D support a virtual machine simply won't do. If it is just business apps a virtual machine runs just fine.
I have been testing Windows 8 Enterprise edition for 90 days on my PC, I am using it right now to make this blog entry. I always use the things I write about. I'm finding a lot of legacy Windows apps won't work in Windows 8, but hopefully they will be rewritten or have newer versions to replace the ones that won't work. Bad luck if you need Visual Studio 2002/2003, or you have a PLC RLL software to control your PLC devices. I'd pick Windows 7 over Vista any day of the week, and dual boot to Windows XP for those old applications that need it for a legacy Windows PC.
Linux is gaining a lot of support as a Windows 8 alternative, with the WINE (WINE Is Not an Emulator) program some legacy and modern Windows apps can run under Linux. WINE exists for other Unix like platforms. But Linux itself has countless free and open source software programs you can use for free, and others that are commercial you can buy. Ubuntu seems to be the favorite as 12.10 just rolled out.
The Macintosh, Mac OS X, well you have to buy a Mac to use Mac OS X to be legal. There are Hackintosh PCs out there that can run a modified Mac OS X but it is not as modern as Mac OS X 10.8 Mountain Lion, IIRC The Hackintosh Mac OSX86 is still 10.6.2 last I checked. Basically if you need Mac OS X apps buy a Macintosh, if you just want a Unix system try Linux like Ubuntu which can have the Cario Dock added and Mac OS X skins added to have a Mac look and feel for free without violating Apple's EULA/TOS.
ReactOS, a free and open source operating system that is trying to rewrite itself as a Windows 2000/XP/2003 clone, and might be sued by Microsoft if it gets too popular. Using the WINE program it tries to run Windows apps and use Windows drivers. It is still in alpha testing and not ready for prime time, but give it five to ten years and it might become something. Don't use it unless you run it in a virtual machine.
Haiku Project, a free and open source rewrite of BeOS. It too is in the alpha stage but it is more stable than ReactOS. It won't run Windows apps, but will run some old BeOS apps. If anyone remembers, Apple was going to buy out Be Inc. and base the next Mac OS on BeOS, but changed its mind and bought out Next, Inc. instead and got back Steve Jobs and turned the BSD Unix based NextOS into Mac OS X. Run this in a virtual machine because it is not stable enough for bare iron yet, and make sure you set a serial port for the debugging part or else the virtual machine boot will crash.
AROS, AROS Research Operating System, this is a much better free and open source operating system than ReactOS and Haiku, but it won't run Windows apps. It is an AmigaOS type OS that can run some legacy Amiga software, and they are developing new software for it. In a few years it might be worth installing on bare iron PCs once they update the drivers and add in a good and decent email and web browser to it. I can really see AROS ported to ARM chips and used in touchscreen devices.
eComStation, honk if you love OS/2! This is the modern day version of IBM's old and busted OS/2 operating system for modern hardware. Sure you pay a lot to license one but the right package has Lotus Smart Suite included and of course the OS/2 version of OpenOffice.Org and access to a suite of free and open source software ported to OS/2. OS/2 was a better DOS than DOS and a better Windows than Windows, but Windows 95 and up killed it dead. IBM eventually licensed an OEM of OS/2 to Serenity Systems International and a lot of legacy OS/2 code is still used in international bank ATM systems and banking systems. I was amazed when I visited Thailand, for example, that the ATM near me showed the "OS/2 Warp" logo after a reboot during a thunderstorm when we were at an island resort. I found out these are all over the world and not replaced and needs OS/2 systems to communicate with them as it was never ported to Windows. There is a thing called ODIN that functions like WINE to run 32 bit Windows programs on eComStation.
FreeDOS, yikes, you really don't like Windows 8 so much that you'd consider downgrading to DOS to avoid it? MS-DOS won't run on modern PC systems, or at least not access all the memory and other stuff? Try FreeDOS the 32 bit DOS that is free and open source. I think in some cases there is a FreeGEM you can run on top of it for a GUI, if anyone remembers the old DRI GEM that used to compete with Windows 3.X way back when?
SparrowOS, well this used to be LosethOS but it was renamed. Imagine if there was a hybrid Commodore 64/Amiga 64 bit operating system with C/C++ added instead of BASIC and of course no TCP/IP stack, no serial ports, no 3D support just 2D, and it was written by a mentally ill person on disability who claims you can talk to God in it. I mean it has hymns in it, that is how religious it really seems to be. You'd have to be really really mad at Microsoft to use this OS, or get revenge on your friend or boss by installing this OS on their PC and watching their face trying to figure it out. For recreational use only, if the government would only legalize it. :)
Android tablets, yeah they get very cheap these days. So cheap they forced Apple to make an iPad Mini. Ditch the PC unless you want to install Android X86 on your PC. That might just work as any device can become an Android device.
iOS devices, be it iPad Mini, iPod Touch, iPod Nano, iPad (Maxi Pad?), the iPhone or whatever else Apple comes out with, iToaster, iRefridgerator, iAutomobile, Apple TV, maybe even bringing the Apple Newton back from the dead as an iOS device? They can be used instead of a Windows 8 device and if you don't mind an on-screen keyboard they work quite well.
My favorite choice is Ubuntu, it is free, it is fast, and it is easy to use. It is the cheapest solution to avoiding Windows 8 if you don't mind a bit of a learning curve, well Windows 8's GUI causes a new learning curve so why not try Ubuntu out?
Don't forget if you buy a Windows 8 PC and reformat it and put on a new OS to ask for a refund and return the Windows 8 disk and license. Let Microsoft know that Windows 8 is the New Coke of Windows operating systems.