It has officially been half a decade since the original iPhone was introduced on June 29, 2007. Not long. But technology years have become more and more like dog years—five human years is simply not a modest amount of time for a product like the iPhone to be on the market; it has become an eternity.

So it can be hard to remember that the iPhone's launch in 2007 permanently changed the smartphone. It left (and is currently leaving) its mark on the handset scene altogether; it kicked into gear a burgeoning mobile app industry that would be hard to live without today. And Apple now seems perpetually embroiled in countless patent suits with its competitors over what former Apple CEO Steve Jobs described as "a great theft" of Apple's designs.

The tech world has changed so much in those five years since 2007, yet Apple has largely stayed true to its original product vision. On this five-year anniversary of the iPhone's launch, let's take a look back at how the iPhone has evolved, as well as the evolution of the operating system that comes with it.

Original iPhone and iPhone OS 1.0: "We love the concept..."

It's clear to us that the iPhone wasn't meant, at the outset anyway, as a smartphone for smartphone people (who typically end up being business people). Instead, the iPhone was meant as a smartphone for everyone else: average people who, until now, had no reason or motivation to get a BlackBerry or something similar that may have been more difficult to use and had way too many features for the average phone user.

—Jacqui Cheng, Ars review, July 9, 2007

The original iPhone was a controversial device. The geek crowd was still emotionally attached to the late-1990s idea that Apple was on the verge of death. It was suspicious that Apple would create something that was more than a niche product that would only appeal to a tiny percentage of "Mac zealots." Companies like Nokia openly voiced skepticism that Apple could just jump into the handset market feet-first and be successful. Apple fans were more than excited, but it seemed that the world at large approached the idea of the iPhone with extreme caution.

But the company moved forward, and on June 29, 2007, it released its first foray into cellular mobile devices. The iPhone had a glossy glass screen and a matte metal back. It only worked on AT&T and was not subsidized. Users had to pay full price for the iPhone right from the beginning and still had to commit to a two-year contract. It worked on AT&T's EDGE network, as 3G was just becoming popular. Though a number of other phones already supported it, 3G networks (and corresponding devices) weren't quite at the same level of ubiquity as they are today. (For reference, T-Mobile had not even begun to roll out its 3G network yet).

The mobile landscape at the time looked something like this:

But Apple approached the concept of a smartphone a bit differently—so differently, in fact, that there was much debate about whether the iPhone even qualified as a "smartphone." Unlike most smartphones, the iPhone had only one button and no hardware keyboard. Its enterprise features were lacking—there was no Exchange support, and IT admins were extremely limited in their control over the device for business users. But Apple also made it easier for consumers to sync the iPhone with their computer in order to sync their music, e-mail accounts, photos, contacts, and more.

Evolution of the iPhone June 2007: Original iPhone and iPhone OS 1.0 debuts, touting a full-featured Web browser. No hardware keyboard and no third-party native apps. : Original iPhone and iPhone OS 1.0 debuts, touting a full-featured Web browser. No hardware keyboard and no third-party native apps. July 2008: iPhone 3G and iPhone OS 2.0 bring 3G speed, GPS capabilities, and (finally) developer access. June 2009: iPhone 3GS and iOS 3.0 are the first update without a major redesign. Increased speeds and iPhone OS becomes iOS. June 2010: iPhone 4 and iOS 4.0 come with "improved" antenna, "retina" display, and "multitasking." October 2011: iPhone 4S and iOS 5.0 are part of the first launch under Tim Cook. Siri is introduced in beta, revamped notifications come to iOS. October 2012 (?): "The new iPhone" (along with iOS 6) is rumored for the fall with any number of potential features.

One of the main features of the iPhone was its full-featured browser. The thing could actually visit normal webpages like those displayed on computers. This was practically unheard of—most handsets at the time largely made use of awkward mobile browsers that could only load awkward mobile websites, which themselves were rare. This was a major move on Apple's part.

And if you had to reformat your device, you could restore it completely from backup from your own computer. Outside of enterprise users (who mostly had BlackBerry devices), regular consumers weren't used to this kind of feature on their phones. (I was pretty happy to be able to successfully transfer a single MP3 to my RAZR over Bluetooth back then. And it was extremely common for friends to completely lose their entire contact lists on a regular basis. Remember those times when you'd text a friend and they'd respond, "Who is this? My contacts got deleted.")

But one thing that upset developers and consumers alike was that Apple wouldn't allow third parties to develop native applications for the device, which ran what was referred to as iPhone OS (version 1.0). Apple announced just before the iPhone's release that developers would be able to create capable Web apps using new Web technologies, so there was no need to create native applications. The developer world was not pleased with this news, but they went with it because...well, what other option was there? Apple later realized that this was a mistake, and would eventually change course on that decision.

iPhone 3G and iPhone OS 2.0: "Hitting the 3G-spot"

The clamor leading up to the introduction of the iPhone 3G was palpable. People had whipped themselves into a froth over the idea that the iPhone could finally gain 3G capabilities and see wireless data speeds so fast, their entire lives would be changed. Perhaps that expectation was a bit on the hyperbolic side, but the iPhone 3G's arrival brought the phone more in line with its higher-end competition. Customers were excited.

When Apple released the iPhone 3G, it also redesigned the phone. The back became a rounded, easily scratchable black plastic. The camera was mostly the same (save for a slightly larger lens and it being ever-so-slightly recessed), but hey, at least the speakers became better (and louder). Apple also added GPS capabilities to the iPhone for the first time.

More importantly, just months before the release of the iPhone 3G, Apple had given in to developers and announced a real iPhone SDK for producing native apps. (Ars exclusively reported in late 2007 that Apple still had no plans to release such a thing. This was later confirmed in 2011 by Walter Isaacson's biography of Steve Jobs, which said Jobs was adamantly against third-party apps until there was so much internal and external pressure that the company could no longer resist). The introduction of the App Store was a major step forward for both the iPhone itself and its platform—then, iPhone OS 2.0. The App Store made its formal debut alongside the launch of the iPhone 3G.

Mobile apps, on their most basic level, were not new at this point. But you would think they were, given how explosive the market became in a short period of time after the App Store's initial launch. Smartphone users weren't used to being able to go to a centralized "store" to find and download apps for their devices from a huge variety of companies. (Up until this point, smartphone manufacturers largely treated their platforms like computers, where users would have to locate and install third-party software on their own. And that software was rarely good—developers almost never had guidelines or high-quality SDKs to work with). Developers instantly recognized the value in offering native iPhone apps through the App Store even if they also offered mobile Web apps. Over time, the concept behind the App Store eventually made its way over to a plethora of other platforms.