- Apple's IPO in 1980 kicked off the personal computer era. Apple's IPO kicked off the personal computing era, but the company blew its early lead. IBM launched its PC a little later, but it really took Microsoft to open the PC market to dozens of low-cost clones, crystalize the vision -- a computer on every desk and in every home -- and figure out that software, more than hardware, would drive adoption.
- Netscape's IPO in 1995 launched the Internet era. Before Netscape, the Internet was a tool for academics and nerds. Six months after Netscape went public, the phrase "dot-com" started showing up in TV commercials, and dozens of eventual Internet giants -- from Yahoo to Amazon -- followed. Netscape eventually got crushed by Microsoft's decision to bundle Internet Explorer with Windows (as well as by its own missteps), but the dot-com era was no doubt the Netscape era.
- The launch of the iPhone in 2007 began the mobile era. Palm, RIM, Microsoft and a few other companies had built combination phone-computers before 2007, but Apple took the concept and pushed it into the mainstream, with a lot of help from Google's fast-following Android and all its hardware partners. In a short five years, Microsoft has lost its monopoly on Internet-connected clients, everybody has an "app store," and (as William Gibson once pointed out), the silhouetted figure of a person checking a smartphone has replaced the cigarette smoker as the most common scene on a city street.