Why is there an "@" symbol in your email address? Why do we type "http://" when visiting a website? Why have we spent so much of our lives trying to hit the Ctrl, Alt, and Delete keys at the same time? There are any number of reasons the little quirks of modern computing find their way into our daily lives and end up staying there for years on end. But you can often trace such arcana back to a very personal moment, when a particular computing pioneer had to make a choice. Sometimes, these choices were random. Sometimes, they were carefully thought out. But chances are, they weren't made in an effort to change the course of the computing history. The choices were made. And, for some reason, they stuck. Here, we take a quick look at some of these picks from heaven (see images above), and if you can think of more, do drop us a note. We begin with Tim Berners-Lee, who appeared last Friday in London during the opening ceremonies of the Olympics. Berners-Lee invented the worldwide web while working at Switzerland’s CERN nuclear research lab in the late-'80s and the '90s, but he hails from Great Britain. As it hosts a third Olympics games, Britain took the opportunity to remind the world that the web started with one of its own. The world now seems to think that Berners-Lee founded the entire internet, but that's not Britain's fault. The origins of the internet can be traced back to the 1960s. What Berners-Lee did is invent the web browser, a way of sharing information across the internet and linking it all together with hypertext like this. He's the one who decided that every web address should begin with "http://". No, it's not the most elegant of choices, but he makes no apologies. When he designed the web address, Berners-Lee recently told us, it wasn't supposed to be seen by the average web user. It was meant solely for the technicians behind the scenes. "On the initial design of the web, you didn’t see the http:// when you were a user. You just read text and you clicked on links," he said. "In the original web browser, you had to bring up a special link inspector to see addresses. That’s why I wasn’t worried about http:// being ugly. No one would really see it." HTTP is short for hypertext transfer protocol, the basis for moving web pages across the net. And he used that colon and those slashes because they were things the computer wonks of the day would be familiar with. The double slash was inspired by a file system for a computer workstation of the day known as the Apollo/Domain. "The double slashes were there because, on some computer systems, that was already used to mean: ‘We’re going outside the computer now.’ The single slash was for the local file system. The double slash was for the outside." The Apollo/Domain is gone. But those slashes are still here. And they're not going away anytime soon. Image: Flickr/ Pixel y Dixel

Ray Tomlinson is the reason there's an '@' in your email address. In the early 1970s, Tomlinson was an engineer at Bolt Beranek and Newman, a Boston company that played a major role in the creation of the ARPAnet, the forerunner of the internet. He was charged with building a new operating system for the DEC PDP-10 minicomputers that connected to this fledgling network, and one day he decided the thing needed a messaging system. The result was a program called "SNDMSG" command -- short for "send message." Many call this the world's first email program. Others disagree. But there's no denying it's the origin of the "@" symbol. Yes, the symbol sat between the name of the user you were trying to reach and the host computer where you could reach them. "I looked at the keyboard, and I thought: ‘What can I choose here that won’t be confused with a username?’” Tomlinson recently told us. "If every person had an ‘@’ sign in their name, it wouldn’t work too well. But they didn’t. They did use commas and slashes and brackets. Of the remaining three or four characters, the ‘@’ sign made the most sense. It denoted where the user was...at. "Excuse my English.” Image: Flickr whlwcl

Dave Bradley is one of the twelve people who built the original IBM PC. But he's more famous than that. He's the guy who invented Ctrl-Alt-Del. The "three-fingered salute" is now on the wane. But for more than thirty years, this is the way the world started, shutdown, and rebooted their desktops and laptops. While working on the first PC, Bradley got tired of waiting for the Power-On Self Test, or POST, that ran each time he restarted the machine. So he developed a shortcut -- Control+Alt+Escape -- that would let him get around it. Later, he changed the Escape to Delete. And for the next thirty-years, a reboot would require two hands. “It wasn’t some eureka moment. It wasn’t a ‘Watson, come here, I need you’ kind of thing," Bradley told us in 2005. "It was just one of the hundreds of different things we needed to do to build a PC." Image: Flickr/Filippo Minelli

Why is the world's most popular programming language called C? Because it came after B. At Bell Labs in the early 1970s, Dennis Ritchie and Ken Thompson needed a better way to build the UNIX operating system they were working on, so they created C. They called it C because they'd already built a language called B. Depending on who you talk to, B was named either after Thompson's wife Bonnie or BCPL, a language developed at Cambridge in the mid-60s. We prefer the Bonnie story. Image: Flickr/ darthpedrius

If you're using a Mac right now, you'll notice a weird flowery symbol on a key right next to your spacebar. That's the command key, used to quickly access particular tools on the Mac -- and only the Mac. That flowery symbol is there because Steve Jobs didn't like the original symbol on the command key: the Apple logo. We don't quite understand this either, but that's the way it was. Jobs asked Andy Hertzfeld -- the guy who designed the button -- to redo the icon, and Hertzfeld turned to Susan Kare -- who designed many of Apple's icons. Her icon isn't really a flower. It was inspired by a symbol used at Swedish campgrounds to identify a place of interest. How ironic. Image: Wired/Ariel Zambelich

The most important open source software project of all time is called Linux. That's because it was created by a man named Linus Torvalds. Not too exciting, But what about the most important open source project of the cloud computing age? That would be Hadoop. And it's named after a yellow stuffed elephant. Hadoop -- a massive number-crunching platform that runs across an army of computer servers -- was founded by a developer named Doug Cutting. Using two Google research papers as inspiration, he created the platform so he could more easily build an index of the web for an open source search engine he was building called Nutch. Soon, he was hired by Yahoo, and over the last five years, Hadoop has become one of the primary software platforms underpinning the web. It's now used by everyone from Facebook, Twitter, and eBay to Microsoft. Cutting called it Hadoop because he needed a name no one else in the tech world had used. And Hadoop is what his young son called his yellow stuffed elephant. Cutting recently told us his son is demanding royalties. "I’ve told him I’ll pay his college tuition," Cutting said. Image: Tim Bray/Wikicommons

Alright, this one's kinda gross. Why do we call a software bug a software bug? You can trace the term back to the legendary Grace Hopper, the U.S. Navy officer who built the first compiler for a computer programming language and laid the foundation of the one of the world's longest standing languages: Cobol. In the late 1940s, Hopper was at Harvard's Computation Laboratory, working with early computers known as the Mark II and Mark III. One day, the Mark II stopped working and a man named Bill Burke traced the problem to a dead moth stuck in the machine. The term bug had been used before, but this was something different. When writing up the incident in her electromechanical computer's log, Hopper included the moth. "First actual case of bug being found," the log read. Image: U.S. Naval Historical Center Online Library