I've noticed a lot of fears from long-time Mac users over the Intel announcement. I thought it would be helpful to inform people about it. So, let's stick all the info we know about it here. Add to it freely when you find something out! Edit: Updated with people's contributions. Read the rest of the thread for more info that wouldn't fit in the character-length limit of this post. Will Macs switching to Intel processors mean viruses will be coming to Mac? No. The insecurity of Windows is what causes the propagation of viruses. For instance, OS X user accounts don't run with root privileges as in Windows. Windows also ships with a lot of ports open by default, while OS X ships with none. It's the software running on top of the processor that makes a computer secure or insecure, not the processor itself. Are my Power-based Macs all obsolete and useless now? No. In fact, they'll likely be supported for years and years. NeXTStep, the ancestor of OS X, supported "fat binaries," which are single application bundles that contain executables compiled for multiple platforms. This means one app that can run on different processors freely. OS X also supports this, and Jobs called them "universal binaries" in the keynote. This means application developers can automatically compile a single version of the app that will run on either PPC or x86 Macs. It will happen invisibly to end users. Your Mac is still a beautiful Mac that will continue to run new software for several years. At the keynote, Steve Jobs informed developers that they would be supporting both platforms for a long time to come. Huh? Universal binaries? Applications in OS X are just folders with a certain extension. Finder treats them as a single entity. Inside the folder are all the resources for that app, including the executable file, equivalent to the .EXE file of the Windows world. A universal binary contains multiple executable files inside the bundle. Can I copy apps from OS X PCC to OS X Intel and vice versa, and will they run on either machine? It's too early to know for sure, but apparently the OS X installer will strip out the unneeded architecture from an application when you install it, saving disk space. More on this when developers learn how it all works. What about my older PPC apps? What if they're not recompiled for new Intel Macs? This is what Rosetta is for. Rosetta leverages technology from Transitive Technologies, a company that has developed a way of translating machine instructions from one chipset to another with little to no performance loss. For older apps that don't provide a universal binary to run on the new chips, Rosetta will translate the binary instructions and run the app. Newer Intel chips will be much faster (3.2+ Ghz) and make up for potential drops in performance for these apps. And, of course, today's Macs will continue to run new software thanks to universal binaries. Nobody is missing out. After all, 16% of computer users run Macs. Developers won't be abandoning PowerPC anytime soon. Is this going to be a huge, painful transition? This isn't the early 90s anymore, and this isn't the old MacOS, which was very reliant on the old processors. OS X is based on OpenStep/NeXTStep, which was already very portable and ran on x86, so the operating system is very flexible on multiple platforms. Apple has been keeping secret internal x86 ports of OS X for the past five years. API and compiler technology has improved to the point that the processor is much less relevant. This wasn't the case in the 90s. Because of universal binaries and PPC emulation for older PPC apps that aren't updated, Apple is making the process nearly invisible to end-users. All you'll notice is a much faster PowerBook! And today's Macs will happily run the same software that will be running on Intel Macs, thanks to universal binaries. But don't take my word for it. Steve Jobs has already told CNBC, "It's not as dramatic as you're characterizing it." Ultimately, it's really not. Speaking of which, what the heck are they going to call the PowerMacs and PowerBooks now that we're moving from Power chips? The "Power" in the names doesn't actually refer to the Power-based architecture, as the first Apple PowerBooks used the old 68k chip. Apple will most likely continue to use the names. Will new Macs require the "lawn mower" fans that PCs use? The lawnmower sound of your average PC is due to the cheap design of that manufacturer. G5s generate a lot of heat and require a lot of power, so if you already tolerate the fans needed for the PowerMac G5, an Intel chip will be a big improvement. Will Macs continue to use OpenFirmware? Apple's developer documentation states that Apple will not use Open Firmware in Intel-based Macs. It doesn't specify what they will use in place of it, however. More on this when the information becomes available. Will I be able to run Mac OS X on my Dell? No. "We will not allow running Mac OS X on anything other than an Apple Mac." - Phil Schiller Will I be able to run Windows/Linux/other x86 OS on my Intel Mac? Most likely, but Apple won't support it. "That doesn't preclude someone from running it on a Mac. They probably will," he said. "We won't do anything to preclude that." - Phil Schiller, when asked about the possibility of running Windows on Macs. Source: CNET. Will it make Windows to Mac ports easier? Will it make games faster? It will make little difference in porting Windows applications. As stated before, most of today's software development is dependent on the APIs used, not the processor. A Windows app using the Win32 API to display a dialog box will still need to be changed so that it uses an OS X API to display a dialog box. Direct3D games still rely on DirectX and need porting to OpenGL. Most of today's games rely entirely on the GPU for their advanced graphics, so the CPU is rarely the bottleneck anymore when it comes to framerates. Will we be forced to re-buy software if we want to run x86 native? Will we be forced to run the app in emulation mode? What if the app is G4-G5 only? There are all questions to ask developers. Free updates will probably be provided in most cases. Many developers will probably use the processor switch as an opportunity to release a major version update. The shareware community will probably keep up with Intel compatibility quickly and easily, as they did with Tiger compatibility. Why is Apple switching? Steve Jobs told CNBC: In truth, IBM has been unable to fufill Apple's manufacturing demands in the past, and that IBM's inability to deliver faster and cooler G5s for Powerbooks and faster Powermacs is holding back the Macintosh line. Switching to Intel processors means Apple can continue to deliver upgraded Macs--including Powerbooks that cross the 3Ghz barrier. Will this really be a seamless transition? It should be. Universal binaries provide developers the ability to ship one app that runs on both platforms without issue. Users of today's Macs and future Macs will still be running the same software. Rosetta provides users the ability to run older apps that for one reason or another haven't been recompiled yet. Macs are not suddenly going to become PCs. Macs will still be Macs. OS X will be OS X. Only the processor underneath will change. Will there be an "Intel Inside" sticker on future Macs? Computer manufacturers are not required to have that sticker on their cases. They are provided a financial incentive if they do so, but it's very difficult to imagine Steve Jobs compromising the visual design of Apple machines for extra cash. It's unlikely. What does this mean for Apple's competition and other groups? There are new things to consider with the use of an Intel platform, all of it speculation: WINE, a free port of the Windows API written by independent developers, may allow Windows applications to run unchanged on a Mac at near-native speeds. Linux users already use such technologies to run Microsoft Office. Virtual PC will be much, much faster because it won't need to emulate an Intel chip when running on an Intel-based Mac. Groups like PearPC will probably attempt to get OS X running under Windows with near-100% performance. It is entirely possible that this is doable, though one would assume Apple would be fully against it.