The IBM PC was as the reason that Microsoft's DOS became the defacto standard for PCs. DOS has some competition with Digital Research's CP/M but we know where Microsoft wound up. There was also the USCD p-System based on Pascal. UNIX ran on mini and mainframe computers. Linux was a gleam in Linux Torvald's eye.
The IBM PC was not the only "personal computer" nor was it the first. I was working on a platform from Epson called the QX-10 that ran an operating system and application platform from Rising Star Industries called Valdocs. It was actually more advanced than most systems out there but the QX-10 ran a Z80 albeit with 256 Kbytes of RAM.
The IBM PC ran IBM DOS on a 4.77 MHz Intel 8088. It came with 16 Kbytes of memory that could be expaneded to 256 Kbytes. It also had up to two 160 Kbyte floppy disk drives. Anyone seen a floppy disk drive lately?
The IBM PC with two drives weighed in at 25 pounds. It was 20-in by 16-in by 5.5-in not including the monitor (17 pounds for monochrome) or keyboard (6 pounds). Compare this Apple's latest iPad 2 and there is no comparison. The iPad 2 runs a 1 GHz, dual core A5 with 512 Mbytes of RAM and up to 64 Gbytes of flash. The IBM PC had serial and parallel port options while the iPad has built-in WiFi with a 3G option. The iPad's color LCD screen has a 1024 by 768 resolution that IBM didn't pick up until the VGA adapter was available. The IBM PC started with a 640 by 480 resolution.
The iPad 2 has lots of things that the IBM PC could never do. It has a pair of digital cameras (front and rear facing). Its battery runs for 10 hours and it can handle 1080p streaming video.
There was a "portable" IBM 5100 and Compaq made its mark with a luggable 386 IBM PC-compatible. Laptops can trace their roots back to Epson's HX-20 (I had one of these).
The IBM PC was launched in a much different climate than when Apple's iPhone was released over 25 years later. IBM tried to keep the competition away essentially generated clean room BIOS companies like Phoenix Technologies. This led to a plethora of competing hardware vendors. I was Director of PC Labs at PC Magazine and we had thousands of machines tested in the Labs.
The technology and market grew because of the open architecture that IBM allowed. It did try to clamp down with its Micro Channel Architecture (MCA) six years later with its PS/2 line. It was not a flop but it never achieved the support of market share that the PC-compatible systems employed. MCA was technologically advanced but the PCI standard brought MCA's functionality in an open fashion.
Apple's control of the iPad and its iTechnology in general exceeds that IBM tried to do with the PS/2. In many ways, Apple has been more successful than IBM was in that account. Google's Android is the main competition for Apple and its more open environment tends to be one reason for its adoption. In many ways, Android can trace its roots to the IBM PC since Linux, that Android is based on, was designed to run on the Intel 386.
I never actually owned an IBM PC although I worked on many. I tended to go with the lower cost alternatives. I also customized MSDOS for many non-IBM platforms.
It is worth looking at what made the IBM PC and the PC-compatible market a success. On the software side, it is what is driving the Apple and Android app stores. Unfortunately, the hardware side is significantly hardware because it is essentially closed even on the Android side. It will be interesting to see what the computing environment will look like in just ten more years let alone another 30. It could be exciting if the amount of computing power grows by even a fraction of what it has beeen in the past 30 years.