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There has for some time been much confusion about what an operating system is and what makes a good one. So I've taken the time to offer a bit of clarity.

Operating System

An operating system is the software that operates the system. It's a self-defining term. An operating system does a lot of important stuff that most people are completely ignorant of and don't give a damn about except that those things affect whether or not the computer works and how fast it is. The system that the OS operates is the hardware and many OS entities that support running applications and other software on your computer. Such entities include processes, threads, file handles, network stacks, memory blocks, and so forth.

The operating system essentially does two things. It handles the operating the hardware and managing resources. This is why it's called an operating system. The second, and equally important, thing that an OS does is act as an Application Programming Interface or API for all other software so that the other software can run and interact with the hardware as well as each other. In Windows, there used to be an API called Win16. That's now retired. Today Windows offers two distinct APIs called Win32 and Win64, which are 32-bit and 64-bit versions.

Windows 3.1 and earlier were not operating systems, but rather graphical shells that ran on top of the operating system called DOS. OS X and iOS also are NOT operating systems but rather platforms -- I'll define that soon -- that run on top of the operating system. The last operating system that Apple wrote was OS 9 in 1999, which was such a flaming piece of shit that Apple decide to stop even trying to write OSes. This was in fact one of the best decisions Apple ever made, and I mean for Apple. The other best decision Apple ever made was to stop making hardware and simply use PCs.

PC or MAC

The term Personal Computer or PC originally meant any computer an individual could earn. It had to be cheap and small compared to the mainframes and minicomputers. A minicomputer was barely the size of a refrigerator. In the 1970s, this was considered small. PCs were any microcomputer. Today we don't use the term microcomputer, but rather desktop and tower. Later came the laptop, tablet, and phone form factors.

By 1984 the term PC did not mean any computer owned by an individual because the entire microcomputer industry was boiled down to two players, Intel and Apple. PC then meant any computer based on the Intel x86 line such as the 8086, 80286, 80386, 80486, 80586 or Pentium I, etc. Intel stopped using the 80x86 names because it couldn't trademark them due to a court ruling that they were descriptions. So, in order to market against AMD, another company that made x86 CPUs, Intel trademarked "Pentium" and started calling their chips by that name, which is why today it's far more confusing which chips precede which.

On the Apple side, Apple made computers like the Apple I and Apple ][ and eventually the Lisa, which quite frankly were armature hobbyist quality. These were the only true Apple computers in the fullest sense. This all changed when the executives at Xerox corporation, the makers of photocopiers, made one of the stupidest mistakes in history. They showed Steve Jobs the work of the great Douglas Engelbart.

Douglas Engelbart invented the mouse, the graphical user interface, and Ethernet. His inventions were decades before their time. Steve Jobs saw these inventions and, as was common in the early days of computing, ripped them off wholesale. And the Apple equivalent of the graphical user interface was a piece of shit compared to Engelbart's already completed version.

So Apple went on to build the Macintosh, which used the Motorola architecture. Motorola is a company with a long history of embedded computing (think electronic security doors, building automation, cell phones, processors in various parts of automobiles, etc.). Specifically all true Macintoshes, i.e. before the PowerPC, used Motorola 680x0 chips from 68000 to 68040.

However, Apple wasn't able to compete well against the Windows/PC (or Microsoft/Intel) alliance using the Motorola chips. The Intel chips were just better for desktop computing. Not that the Motorola weren't great for embedded devices, but Intel offered faster machines that could do more.

So Apple and IBM got together and tried a new idea, Reduced Instruction Set Code or RISC. The idea was to eliminate most operations a CPU could do, so that the CPU's clock speed could be drastically increase. The CPU would have to execute more instructions to do what an Intel chip could do with one complex instruction, but the CPU hopefully could do each simple instruction much faster. However, RISC turned out to be a flop. First, the Intel chips were always clocked faster than the PowerPC chips, completely defeating the purpose of the entire RISC architecture. Second, the complex instructions were just quite frankly awesome and made a lot of things like playing and editing video possible.

So Apple abandoned the PowerPC, which despite its deceptive marketing name was not a PC, and simply moved to the PC platform. Remember, the term PC and the term Windows are completely different. Windows is an operating system that runs on PCs and other devices (phones), and PC is a computer architecture that can run a multitude of operating systems including Windows, OS/2, OS X, Solaris, Linux, etc.

Now using PCs as the basis for their products was a great improvement. Intel released the MMX and later XXM instruction set, which are CPU instructions that deal with massively parallel arithmetic operations designed to support multimedia. These instructions are beyond awesome. Unless you've written multimedia code in C, ported to assembly to double its speed, and then wrote XXM code to increase the speed by two to three orders of decimal magnitude, you don't comprehend how awesome these instructions are. I do not exaggerate when I say that without these instructions, video playback and certainly video editing would be impossible on computers. And Apple made the transitions to PCs right when multimedia was taking off. If it hadn't, the entire Apple experience would have ended.

Today, the only computers that you use that are not PCs are your tablets and phones. Well, some tablets are PCs, but others like the Google Nexus 10 are not. Intel has recently entered the smartphone market, but I don't know if their chips are following the x86 architecture or not, and Intel has a lot of catching up to do. I'm sure the executives at Intel are kicking themselves, or more likely their engineers, for missing the smartphone boat ten years ago.

Hopefully at this point you have a firm grasp of what an operating system is and what a computer platform is, and what the differences between the two are. There is a many to many relationship between OSes and computer platforms. A single platform like the PC can run many operating systems and can even have dual or multi-boot to different installed operating systems. Similarly, any operating system can be ported to multiple computer platforms. Typically operating systems have some kind of hardware abstraction layer or HAL to make this easier.

Software Platforms

So if OS X and iOS are not operating systems, despite their deliberately deceptive marketing names, then what are they? Just like there are computer platforms like PC, PowerPC, MAC, PDP, etc., there are also software platforms.

A software platform, hereafter shortened to just platform, is software that supports other software (apps, services, etc.) as an intermediary between that software and the operating system. An application that is native to the operating system directly calls the API the operating system supplies to open files, send messages over the Internet, allocate memory, etc. A platform application calls the API exposed by a platform instead of the API exposed by the OS.

So why use platforms? The first obvious reason is to make your application independent of operating systems so that it can be used by all users. Examples of platforms that you use that do exactly this are web browsers, Adobe flash, Java, and .NET (well, .NET to some extent).

Some platforms are not meant to provide universal access to applications, but rather perform other services for applications for various reasons. For example, Android, OS X, and iOS are all platforms, and each performs certain functions such as garbage collection, providing a GUI framework, providing an app store, managing application permissions (access to things on your computer), etc.

Other examples of platforms, in a more general sense of the term, include web servers like Microsoft IIS or Apache Tomcat that host web applications and web services and provide various services to the hosted software including lifecycle management, load balancing, parallelism, etc.

So platforms perform very useful services that allow application development to be simplified and allow applications to run more smoothly.

It is important to note that there are two kinds of platforms, managed and unmanaged. There is a world of difference between these two kinds.

An unmanaged platform such as iOS provides an API and frameworks for supporting software, but the execution of that software is performed natively by the operating system. For example, an application written in Objective-C gets compiled into the machine language code of the architecture on which it is going to be executed just like an unmanaged application would.

A managed platform such as Java or .NET provides a virtual runtime environment or virtual machine that exposes both virtual instructions and an API that completely abstracts the underlying hardware and operating system. For example, a Java application runs inside a process that hosts a VM. When the Java application performs any operation it does so through a Java Virtual Machine (JVM) instruction that the virtual machine translates into a native CPU instruction. Although this might seem slower, and it was in the early days of Java (the 1990s), is can be done just as quick, and in fact, even quicker using various techniques including Just In Time Compiling.

[Side note: There may be times when executing native code is necessary, and there are mechanisms for doing that in managed platforms.]

Managed platforms offer a large number of benefits including preventing malicious or wayward applications from compromising a system (no core dumps or blue screens of death), sandboxing applications, garbage collection, portability of execution, standardized serialization, run-time optimization of code, better exception handling, etc. In my opinion, managed platforms are vastly superior to unmanaged platforms, which are so 20th century.

Android is Google's implementation of the Java managed platform and is designed for tables and smartphones. Sun Microsystem, now bought out by Oracle, created three versions of the Java platform. Java Standard Edition was the baseline that ran on desktops and servers, and it was awesome. Java Enterprise Edition added a lot of features geared towards big corporate IT needs, and almost all of it was terrible and led to a backlash and the term Plain Old Java Object or POJO.

Java Microedition or JME was Sun's attempt to scale down Java to run on phones, which at the time had very limited resources. This turned out to be a big mistake. Over the next 15 years the smartphone would become exponentially better, faster, and more capable. The progress in smartphone technology has been astonishingly fast. Today's smartphones are basically tiny versions of what desktop computers were in the start of this century. Sun's scaled down version of Java was essentially worthless and it didn't have to be.

Google took the opposite approach years later. Google realized that smartphones would be fast enough, have enough memory, have enough storage, have enough resolution to do the things that desktops could do. So Google started with Java Standard Edition and built it up rather than scaling it down. Android is essentially a version of Java SE that is customized for smartphones and tablets by adding support for all the hardware features in mobile computing like GPS, orientation, cameras, telephony functionality, etc.

The fact that Android is a managed platform and iOS is not is one of the reasons I consider Android to be vastly superior to iOS.

So, OS X and iOS are unmanaged platforms that run on top on an operating system, but what operating system?

The Operating Systems of Phones

There are multiple smartphone/PDA operating systems. You may have heard of Palm OS, one of the first for PDAs (hand-held computers that were popular in the 1990s). Palm OS was great for its time. Another OS that runs on smartphones is Windows CE. It was Microsoft's attempt to make the smartphone and tablet feel like a desktop. This turned out to be a mistake. Microsoft later made the opposite mistake by trying to turn the desktop into a tablet with Metro -- cringe.

You may be surprised to hear this, but your iPhone runs the same operating system as my Android. That operating system is called Unix.

Well, it's better to think of Unix as a family of operating systems. It used to be an operating system that was created by Bell Labs back in the 1960s, and it still has all the baggage from back then. But the code base has been forked, that is copied and diverged, so many times that there are many different versions of Unix, each best thought as a different operating system with a lot of common concepts, implementations, and history. For example, IBM has a version of UNIX called AIX. Sun Microsystems had Sun OS and later Solaris. Silicon Graphics, think of all those Pixar movies, has Irix. DEC had Ultrix.

And then one man, pissed off at how expensive UNIX was to license, created his own version named Linux. In 1991 Linus Torvalds created a royalty free version of UNIX that immediately became widely popular. By the late 1990s, Linux itself had been forked so many times that it itself was a family of operating systems called distributions or distros.

In the late 1990s when Apple realized it could not maintain its shitty operating system -- MAC OS was the operating system equivalent of Internet Explorer -- Apple decided to use Linux UNIX as the operating systems of all its products. This was the best decision Apple ever made, and damn they were lucky. If Linus Torvalds hadn't created Linux in 1991 and Linux hadn't become so popular, Apple would have died in the early 20th century. This is not an exaggeration.

Apple simply could not maintain its crappy OS. All other operating systems supported multimedia and multithreading and a host of other things. Apple couldn't even implement multithreading into its OS, and that was a necessity in all modern computing.

By adopting Linux, or if you prefer, BSD UNIX as its operating system of choice, Apple got everything for free. It could now do true pre-emptive multitasking with multithreading. It got much better multimedia support. And, most of all, Apple gained entry into every market including the critical smartphone market. Unix runs on smartphones. Apple's operating system, OS 9, did not and could not. For this reason alone, Apple should give half of its wealth to Linus Torvalds. He did far more for Apple than Steve Jobs ever did.

OS X, in all its versions, is simply an unmanaged platform that runs on top of Unix to provide a desktop shell and an unmanaged API, most of which is a pass-through to the UNIX API. That's not to say that these things aren't valuable, but OS X is not an operating system in any sense of the term. Its name is a marketing lie, a deliberate misnomer.

iOS, likewise, is an unmanaged platform that runs on top of UNIX on iPhones. Android is a managed platform that runs on top of UNIX on various smartphones and tablets. If you look at the file system on an iPhone and an Android phone, you'll see the same directory structures, operating system command-lets, and Unix's equivalent of Windows' DLLs which are called shared objects and have the .so extension.

[Side note: I recommend Easy File Explorer for managing your file system on Android machines. It was the very first app I installed on my tablet and on my phone. I don't know if there is an iOS equivalent.]

Most of the time when non-professionals are talking about whether they like MAC or Windows, iOS or Android, they are really just talking about the desktop shells offered on those platforms or OSes. This is a very shallow way of judging a car. Sure, when you buy a car, it's nice to have the color you like. It's also nice to have a reliable, fuel efficient engine and a transmission that isn't going to break down when your in the middle of nowhere. The OS is what's under the hood. The desktop shell is like the dashboard. You can replace the dashboard of a 1984 Ford Ares with something more modern and appealing, but you're still driving a 1984 Ford Ares.

[Side note: Three out of five Ford Ares drivers have fixed addresses.]

The Future

Personally, I'd like to see an entirely new, modern operating system created. I don't mean a new revision of that crappy old Unix from the 1960s. Yes, there are reasons I'm no fan of Unix, but they go into technical details that few people would be interested in. Nor do I want a better version of Windows as it has too much baggage as well. And OS X, iOS, and Androids are platforms, not operating systems. Yes, platforms are important, but so are operating systems.

Over the past 20 years, most operating system development hasn't really been OS development. It's been changing fashions of desktop shells. Let's remove the borders and chrome around windows. Let's snap windows to half or a quarter of the screen. Let's show all our apps as tiles in a list. Let's provide an app store as a single point of buying and installing apps. These aren't real operating system issues.

You might be thinking that the operating system is irrelevant now, and to some extent you would be rights. Sharing documents and interacting is now all done over the Web, which is essentially a distributed platform. Most of the things you do from sending emails and IM to reading news to banking is done in a browser that is largely independent of the underlying operating system.

However, I believe there is a third generation of operating systems that needs to be created. The first generation of OSes were basically bundles of I/O functions loosely placed into an API of sort. The second generation of operating systems provided hardware management in the form of UNIX in mainframes and Windows NT and OS/2 in desktops. They dealt with memory management, processes lifecycles, graphic adapters and gaming, and eventually multithreading and networking.

The third generation of operating systems should provide management of applications, communication, and content. I'm not talking about low-level functions already provided by OSes like talking over the network. I mean high level management of the ecosystem we now live in. A third generation OS would provide every application or service with its own environment and prevent one application from affecting another application's or the OS's environment. For example, no virus could write its code into another application's code. You could see every application on your system and there would be no place to hide because each application would have to be registered in order to even exist on the file system, nonetheless execute.

A third generation OS would also ensure that applications didn't send your credit card information across the network without your permission. Encryption would be provided by the OS for all network traffic. It would make sure applications didn't call home without your knowledge and consent. It would prevent applications from snooping on your private information like your contact lists and what other applications you have installed. All inter-application and inter-process communication would be done through OS channels. It would prevent key loggers and any other kind of spyware.

A third generation OS would provide full content management of your content from photos to videos to saved games in a way that would both simplify tasks and empower the end user. I'm not just talking about backing things up to the cloud or providing specific folders for different kinds of content. I'm talking about managing all your content, protecting it from loss or unauthorized viewing, encrypting it, copying it between machines, sharing it with other people, and even version controlling and face-tagging, and searching it by similar content.

There are a lot of improvements to make to the operating system layer. Why is it that we only get different color pixels every few years?

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