Handy rules of thumb can help you make even the most complex decisions more manageable. A former Bain consultant offers a great one.

Being a business owners means making tough decisions. Sometimes the stakes are high, sometimes the information is incomplete, and sometimes the environment is volatile—and sometimes all three—which means making the right choice for your company incredibly challenging and stressful.

Wouldn't be nice if there were simple tricks to take these complicated, insomnia-inducing decisions and boil them down to something more manageable?

That's just what former Bain & Company consultant Daniel Shapiro offered in a recent LinkedIn post. Drawing on his experience at Bain, Shapiro shares a handy trick that can help owners break down and tackle even the most complex issues. He writes:

If you’re faced with a choice of whether or not to do something, just ask yourself, “What would I need to believe for this to be the right decision?” This simple question is incredibly clarifying.

Here’s an example: I’m trying to decide whether or not to prioritize the development of a new product. In order for that to be a great idea, I would need to believe the following assertions:

We have the team capable of building the product

Customers will buy the product at an attractive price if we build it

We have the distribution to reach potential customers at a reasonable cost

None of our competitors can replicate this offering in the next 12 months

There are no higher priority development opportunities for the R&D team

The hardest part of the process is developing the list of assertions. If you’re having a hard time, grab a colleague – two brains are better than one. Once you have your list, begin analyzing each assertion with data. If you can’t get data to help determine whether or not an assertion is true or false, simply make an educated guess. If any of the assertions are false, it’s probably the wrong decision.

By using this technique, Shapiro asserts, you are forced to break down a complicated situation into its constituent parts and also helps you construct enough structure that you can intelligently and productively discuss the issue with colleagues. Interested in more insights from Shapiro? You can follow him on LinkedIn.

But Shapiro isn't the only devotee of simple rules of thumb—also known, more formally, as heuristics—as a means to help guide us through our toughest decisions. Colin Marshal has rounded up ten useful rules of thumb you can put into use in business and in life, including:

"Can I fail at this?" It's like Raymond Chandler said: there is no success without the possibility of failure. Therefore, something I can't fail at is also something I can't succeed at. I can fail at conducting an interview, writing an essay or making a video. I can't fail at meandering around the internet in search of "neat stuff to read." In a recent tweet, I defined procrastination "the temporary displacement of tasks at which it is possible to fail with tasks at which it is not possible to fail." I suspect I'm less far off the mark than ever, especially regarding why procrastination is not a productive tendency.

"What's the hardest thing I can do?" … my hat tips to Paul Graham: "This is a good plan for life in general. If you have two choices, choose the harder. If you're trying to decide whether to go out running or sit home and watch TV, go running. Probably the reason this trick works so well is that when you have two choices and one is harder, the only reason you're even considering the other is laziness. You know in the back of your mind what's the right thing to do, and this trick merely forces you to acknowledge it."

Meanwhile, author and heuristics enthusiast Ben Casnocha has a wiki of literally hundreds.

What business rule of thumb do you find most valuable?

These common mistakes will ruin your chances of getting just about any job.

Finding reliable, loyal, and competent employees is at the top of most entrepreneurs' minds. You deal with this as a start-up founder, and it continues to plague your management team through the mid-size stage and beyond.

Our company has recently expanded significantly, opening up a number of critical positions. That's pressed us to spend most of our time recruiting--and to learn a lot about the common mistakes that job applicants make.

Using a salary-driven approach to selecting your first job

Opting for a salary-driven approach to the job search--especially when you have little or no experience behind your expectations--is probably not the best long-term strategy. Those once-in-a-lifetime opportunities to gain experience in a coveted field come when you're young and fresh, and the reality is that learning jobs don't pay that well. Being aware of this fact will help you gauge the opportunity better.

As an entry-level candidate, you want to show your prospective employer that you value the experience--and the potential opportunity for growth--more than your initial paycheck.

Using unlikely stories to justify past slip-ups

I frequently find myself speaking with applicants that look great on paper and turn out to be quite different during the interview. If you have unexplained breaks in employment, don't use some crazy excuse in an attempt to make yourself look better. Instead of crafting a sad tale portraying you as the martyr, try using a good old-fashioned truth: "I made some mistakes in the past. Now I realize that I didn't have my priorities properly in mind, and I'm clear on where I'd like my journey to go." It sounds better.

Confusing your employer with a misleading resume

If you acted as director of marketing for your previous employer, but you still haven't graduated from college, don't omit the expected graduation date from your resume. Even if it might get you more interviews, it misleads your potential employer into believing you have more experience than you actually do. This will come clear during the interview, by which time you will have changed from being an interesting prospect to a potentially shady candidate.

Employers are looking for candidates that are capable, reliable, and willing to go the extra mile. My advice: Check your ego at the door, and write a kickass cover letter about why you would be great for the job. Explain your capabilities, and why the company interests you. Recruiters and hiring managers are looking for the next hidden treasure. That could be you.

After getting pushed out of the business she loved, this Cisco co-founder learned a valuable lesson about working with VCs.

In 1984, Sandy Lerner co-founded Cisco Systems with her now-ex-husband, Leonard Bosack, to market the technology they co-developed for connecting computer networks. But after making a bad deal with an investor, Lerner found herself pushed out of the company shortly after it went public in 1990.

After funding the company for three years by mortgaging everything we owned and putting everything on credit cards, we made an absolutely bozo no-no.

We decided to take money from a VC, Don Valentine. He got 30-odd percent of the company for $2.6 million. Len and I were very naïve. We used Don's lawyer and agreed to a four-year vesting agreement. We would get 90 percent of the founder's stock after four years. But we didn't get an employment contract.

When I was fired, it was devastating. I spent years crawling out from that. I did not understand an investor could be an adversary. My family had a small business. I always thought that if someone invested in your business, that meant he or she believed in it. I assumed our investor supported us, because his money was tied up in our success. I did not realize he had decoupled the success of the company from that of the founders.

I don't believe all VCs are adversarial, but the first thing I tell everyone is: Get your own lawyer. Don't buy lines like, "You guys are busy; we'll just have someone draw up some papers, and it will be very pro forma." Yeah, right.

My second piece of advice is to separate yourself from the company. What is good for you is not necessarily good for the company, and vice versa. At Cisco, I made every decision based on what was good for the company, and that pretty much ruined my marriage and my health. Len and I believed a company and its founder are the same. They absolutely are not.

Previous job:Director of the computer facilities at Stanford's Graduate School of Business
First paying customer: Ohio State University
Cisco's current market cap: $112.3 billion

How many times have you heard a company's tagline and thought, "yeah, right!" Here's how to avoid that fate--and make a promise to your customers you can actually keep.

How many times have you read a company's tagline and ended up shaking your head? How many times have you laughed out loud in disbelief?

I'm constantly spotting slogans and ads that promise perfection, but which I know, as a customer, are as far from the truth as Uranus is from the sun. I'm not alone. Nielsen reported that trust in advertising messages has declined dramatically in the past two years.

There are many examples of disingenuous brand promises. Take United Airlines. Please.

As United was in the midst of acquiring Continental Airlines, the carrier posted ads in airports that read, "It's not who's merging that counts. It's what's about to emerge." I can tell you, first-hand, that what's emerged is really nothing to brag about. In fact, it's pretty terrible.

New Jersey Transit is my commute of choice. That's because I have no other choice. A year or so ago, it ran a campaign with the brand promise, "Getting you there.'"

Based upon the daily delays, I suggested it add the word "eventually" to the slogan. And, just last week, after being positively crucified on various rider websites and Twitter feeds, New Jersey Transit launched a new campaign with the brand promise: "We are listening." I chuckled silently, thinking it should add: "...We don't like what we're hearing, but we're not going to change a damn thing. Live with it."

That said, United Airlines and New Jersey Transit have an inherent advantage over the average entrepreneur: They have far less competition (i.e. I have limited options when flying to, or from, Newark Airport and as for New Jersey Transit, aside from choosing to drive and sit in two-hour traffic delays, I have no other choice.

Knowing that, like me, your firm has myriad competitors of all shapes and sizes, how do you ensure you don't alienate--or even outrage--your customers with a bogus brand promise?

1. Know that benefits trump features.

You may be thrilled about selling a computer with a third-generation Intel core processor, but what does that mean to anyone but techies? On the other hand, if your product is simplifying my life and adding a critical minute or two of extra, free time, I'll stick to you like white on rice.

2. Tell your story through the customer's eye.

No one cares if your product, service, or people are smarter, stronger, or faster than the competitors. They want to know that you'll somehow improve their lives. So, if you know I need a car that simply will not break down, don't tell me it takes curves better than Disney's Space Mountain ride. Put your promise in a perspective that makes sense to your customer.

3. Kick the tires before making the claim.

Remember how many traffic accidents occurred when Domino's Pizza guaranteed 30-minute delivery or your money back? A few multi-million dollar lawsuits changed that brand promise virtually overnight.

So, don't do what Comcast, my cable provider, promises in its advertising. Don't tell me you're "Comcastic" when you and I, both know your service is abysmal and your customer service representatives can be more threatening than a New Jersey State Trooper.

4. Tell the truth.

It's a radical thought, isn't it? But, if you've been experiencing product, quality, or service problems and you know that your customers know (the blogosphere always contains more negative than positive comments), you need to admit fault. At very least let customers know you're trying to address the issues.

Loyal customers will stick with you if they think you're being honest with your brand promise. Just think back to that legendary Avis tagline: "We're only No. 2. We try harder." That campaign prompted generations of businesspeople to select Avis over its larger rival, Hertz. And, after all, isn't consideration what you want at the end of the day? Show some authenticity and--gasp--vulnerability in your messaging.

5. Walk a mile in your customer's shoes before you put pen to paper.

Don't tell anyone you're the best at anything before you, yourself, walk in your customer's shoes and know it's a fact. Experience how you are communicating with your customer, online and offline. Test your 800 number. Ask a trusted friend to walk into your reception area and see how she's treated. And definitely, most definitely, test how easy and intuitive the communications experience on your website may be. (Note: we've been in business 18 years, and have updated and upgraded our website numerous times. But, that didn't prevent me from recently discovering we'd been marketing a new service that isn't even mentioned on our website! Needless to say, that fix is being made as you read this column).

To err is human, to forgive divine. Customers will stay loyal if you don't over promise and under deliver. That said, if your product or service truly stinks, it will soon go the way of all flesh sooner or later).

You might be wondering about my firm's brand promise. It's actually both a point of view and a promise: "Listen. Engage. Repeat." We promise clients we'll listen to their audiences before creating any communications plan or strategy. We'll then help the client engage in conversations, both online and off, and meet their audiences wherever they share their hopes and dreams and, eventually, form their decisions. Finally, we'll repeat the process, again and again and again.

That's how we go to market for Peppercomm. And it's how we suggest clients go to market (with our counsel and heavy lifting, of course).

So, what's your brand promise? Would your customers say it rings true? If it doesn't: ask not for whom the bell tolls. It tolls for thee.

One, the maker of the world's most powerful software-development tool is growing at a stunning rate. Two, your next business will be built on it.

It's "Beer:30," and Tom Preston-Werner is standing at a lectern in the vast San Francisco loft where GitHub makes its home. Before him, arrayed on a mashed-up assortment of chairs and couches or topping up a glass of whiskey at the overstocked house bar, are maybe 40 GitHub employees; another 44 around the world are watching a live feed. Preston-Werner has the tired eyes and untended facial hair of a new father, and the low-def biceps of a software engineer. Atop his head sits a mammoth banana-yellow foam-rubber cowboy hat.

The weekly gathering begins with Preston-Werner welcoming a few new employees. The co-founder and CEO then runs through a series of shout-outs to folks who have finished off pieces of code designed either to improve the GitHub site or to make it work better for clients. Then Preston-Werner takes a few minutes to wax philosophical. Taking a page from science writer Steven Johnson's Where Good Ideas Come From, he invokes the importance of "serendipitous interactions," the way powerful ideas can emerge from the most random collisions of people, thoughts, and artifacts. He urges his people--many of them recent hires, most of them in their early 30s, tops--to go out and cultivate new experience, to engage with the unknown. To underline his point, Preston-Werner reminds them that out of the investment the company received in July from Andreessen Horowitz, "about half of a percent" was picked up by Ron Conway, known in these parts as the godfather of Silicon Valley. Preston-Werner met Conway at a Y Combinator conference. Serendipity, indeed.

That venture round was worth $100 million. It valued this little five-year-old company at $750 million. As Preston-Werner speaks, between pulls on a beer, his giant foam chapeau jiggles gently.

As nerd endeavors go, GitHub is pretty much at the top of the food chain. What began as a private project with zero commercial intent has since emerged as one of the world's most--if not the most--powerful development tools for software. In just a few years, it has inserted itself at the center of the developer universe by making it easy for coders around the world to work together. If "software is eating the world," as Andreessen Horowitz co-founder Marc Andreessen put it not long ago, GitHub is where much of that software gets its teeth.

The Andreessen Horowitz bet was the "biggest investment we've ever made," says Peter Levine, the partner who now sits on GitHub's board. It's not hard to see why the VC firm went for it: GitHub's momentum is astonishing. The company says it took 38 months to host its millionth project on the site; the five millionth came in just two months and 21 days. "I don't know a start-up that's not on GitHub," says Jay Sullivan, VP of products at Mozilla, maker of the Firefox Web browser. In other words, your next company, or parts of it, will be built here.

GitHub started as an effort by Preston-Werner and co-founder Chris Wanstrath to solve what Preston-Werner calls a "pain-in-the-ass problem": using something called Git, a version control system developed by Linus Torvalds, the creator of Linux. A version control system is a tool that allows multiple coders to work on the same piece of software without losing track of the various changes made in each version or allowing the source code to be corrupted with lots of contradictory fixes. Torvalds built Git in reaction to the centralized structure of previous version control tools, which made it all but impossible for developers to work together independently. And though Torvalds's system "makes collaboration possible, it doesn't make it easy," says Preston-Werner. He sensed that Git could be "this superpowerful thing if only you could understand it."

Preston-Werner grew up in Dubuque, Iowa; his mom was a special-education teacher and his stepdad an engineer. (His biological father passed away when Tom was a kid.) Preston-Werner was the classic engineer-in-training: ripping apart pieces of gear his stepdad had lying around, hacking the family TRS-80 PC, studying How Things Work books. Eventually, just as the dot-com boom was cresting, he set sail for Harvey Mudd College, east of Los Angeles. After two years, he dropped out to be part of a company run by two fellow Mudd students; then he struck out on his own, first running a digital design firm, which taught him "all of the crap it takes to run a business--taxes, all that," then creating Gravatar, the technology that allows your avatar to follow you around the Web from site to site.

He sold Gravatar to Matt Mullenweg, the founder of WordPress, then paid off his credit card debt and enjoyed the first bit of breathing room he had known in several years. That's when he met Wanstrath, who is still only 27, six years younger than Preston-Werner. ("I started GitHub when I was really young, so I don't have a bio or anything," says Wanstrath, who looks like Gregg Allman run through a reverse aging machine. "My life story's pretty short.") The two were part of the growing crew of developers working in Ruby on Rails, a Web development framework that has itself become a major force. "One of the things we talked about in the Ruby community was Git," Wanstrath recalls, "at the time a very esoteric version control system." In October 2007, they set about improving Git, partly for fun and partly to make it more useful in their professional lives. They stayed in their day jobs and noodled at GitHub primarily at bars and coffee shops around the SoMa neighborhood. During this period, they picked up two other co-founders, PJ Hyett and Scott Chacon.

GitHub went live in February 2008, and soon Geoffrey Grosenbach, founder of PeepCode, essentially demanded to pay for the service. Suddenly, a dork pastime was a business, and by July, Preston-Werner was confident enough in it that he passed up the offer of a $300,000 bonus and stock options from Microsoft, which had acquired Powerset, the company he worked for at the time.

Today, a programmer in Dubai can drop a chunk of code in a "repository" on GitHub's site, post a description of his project and what kind of help he's looking for, and then watch as coders around the world dig in and contribute. If the software is open source (that is, free for the taking by anyone who wants it, with minimal restrictions), the "repo" is visible to all three million developers who work on GitHub.com. Depending on how interesting the idea is--it might be a simple feature for a website or an entire operating system--hundreds or even thousands of people might "fork," or copy, the code and start working to improve it. When a developer thinks he has cracked whatever problem or portion of the problem he was working on, he can make a "pull request" to the "maintainer" of the repository to review his suggested fixes. The maintainer integrates some or all of the new code as he sees fit.

GitHub is in some ways like Wikipedia--highly social, tapping into the human desire to contribute to a common goal. When so many brains are engaged at once, the process of development, refinement, and deployment is radically accelerated. Each revision should, in theory, make the code more powerful, get it closer to the point where it can be shipped as an element in a larger software product, whether open source or commercial. "If the barrier to collaboration is too high, then you're not gonna do it," Preston-Werner says. "But once you get that barrier low enough, once you pass a certain threshold, everybody's contributing." GitHub is adding users at the rate of 10,000 per weekday.

Unlike Wikipedia, however, GitHub has a business model. Essentially, GitHub offers programmers and companies a choice: They can use the collaborative platform for free as a place to build open-source software, or they can pay to use it behind a wall, where they can develop proprietary software that forms part of a commercial product or service. In the first case, your willingness to make your code available to everyone earns you the right to exploit the web of open-source coders working on the GitHub site. In the second, your company's developers work in private, using the collaborative features GitHub has built but not its distributed global network of talent.

"If you have code on GitHub but the whole world can't see it, then you're paying for it," says Preston-Werner. There are three payment tracks. One is a personal plan that costs as little as $7 a month. (The price is based on the number of repositories you have.) Then there is an organization plan, which has features for more sophisticated team management and starts at $25. The big-money option is the enterprise plan, which involves clients downloading a version of GitHub to live locally on their servers. It can cost millions of dollars a year. Enterprise clients include Lockheed Martin, Microsoft, LivingSocial, VMware, and Walmart. GitHub doesn't talk about how much these companies, specifically, are paying, but it has hundreds of thousands of paying customers between the website and the enterprise client base.

Levine, the Andreessen Horowitz partner, says his firm was first drawn to GitHub because it was "a growing enterprise with 300 percent year-over-year annualized growth--in a market that has been unchanged for a very long time." Sounding amazed even several months on, he marvels that the co-founders had gotten to "really interesting levels of profitability and revenue without a dime of outside funding and without even building out a sales organization--they're all engineers!"

A grown-up sales operation, Levine says, is just a first "tactical" step. He and the lads have big plans.

For survivors of Web 1.0, GitHub's offices bring the memories--or night sweats--flooding back. The 14,000-square-foot loft is rigged out with air hockey, Ping-Pong, a pool table, and an Xbox 360 (hooked up to side-by-side flat screens). There's a catered Thursday lunch (families are invited), a fridge full of microbrew, and a handmade wooden kegerator with an inlaid Octocat, GitHub's fantastical mutant mascot. Numerous side rooms house the many other toys designed to "optimize for happiness" for GitHub's 145 employees, who work whenever and wherever they like: electric guitars, an amp, and a full matched set of harmonicas in the jam room; a Skype chamber; a womb room with low lighting, a shag rug, and four egg chairs. There's a ladies' lounge with a pink, plasticized fainting couch, and the executive lounge, complete with faux-antique globe (which conceals a 16-year-old bottle of Lagavulin) and lots of manly leather. Actually, the whole office smells of leather--and revenue, which is what makes it so not like 1999.

If the term open-source software triggers some sort of narcolepsy neurotransmitter in you, you are not alone. It certainly did in me, to the extent that I thought about it at all. But the further I wandered in this world, the more wondrous I found it to be. Those of us who don't write code tend to be oblivious to the sheer labor involved in creating thousands or even millions of lines of the stuff, all of which have to function perfectly if a piece of software is to run bug free. A single project on GitHub can entail months or years of work and countless strings of dialogue among maintainers and coders hoping to contribute.

It's hypergranular work and has to be, not least because open-source software has become the bedrock of almost every company on earth. From Apple to Microsoft to the tiniest start-up, open source is part of the software stack--and many companies are built mostly from open source. And that, of course, is the point: Open source means a new business doesn't have to start from zero; it can pull down prefab pieces of software infrastructure for free, building only the bits it needs to bring its product to life. John Pettitt is founder and CEO of Repost.us, a service that allows news articles to be embedded as easily as video, and to carry their advertising and analytics along with them; earlier, he was the founder of Software.net, which became Beyond.com, and CyberSource, a credit card fraud detection company bought by Visa for $2 billion in 2010. Back in 1994, when Pettitt was starting Software.net, he says, "there was no e-commerce software, there was no e-commerce platform; I had to write my own credit card processing, I had to write my own storefront. Everything we had to do, we had to do from scratch, because there were none of the building blocks there." Pettitt built much of his new company on GitHub. "Today, you can sort of Lego things together in a way you never could before," he says. "And the corpus of information and tools is growing at a huge rate."

Those Legos form the skeletal system of almost every new company; the profitmaking intellectual-property layer is skin thin, sitting on top. "It's no different than having two-by-fours and electricity," Preston-Werner says. "If you have a ready-made Web server and Web framework, for example, that represents hundreds of thousands or millions of man-hours of work that you don't have to put into creating a product."

That is exactly why GitHub is formidable: It is at once a lumberyard and a workspace. Entrepreneurs on the site can find, or help develop, almost all of the open-source raw materials they need and set up their own closed place to integrate those materials with their IP. What's more, by simplifying Git, GitHub has turned a tool even serious coders found arcane into something useful to the "casual forker," in Wanstrath's term. "We want to enable people who don't know each other to collaborate on the same thing, toward the same goal," says Wanstrath. "This is all I want to do--forever."

There has been considerable rumbling lately that the Web is turning into a Monopoly board or mall, with a few big anchor stores and a bunch of rabble scrambling either to build on top of them or to find a survivable place in their shadows. "The openness that drove the Web and its richness are definitely under attack," says Tim O'Reilly, founder and CEO of O'Reilly Media, the producer of industry-leading programming manuals, tech magazines, and conferences. "This happens again and again when something new comes on the scene. There's usually a huge sharing economy, with lots of innovation and lots of openness, and then some animals become 'more equal than others,' in Orwell's wonderful phrase, and then it tends to start to stagnate. But that impulse to create goes and bursts out somewhere else."

That somewhere, at least right now, would seem to be GitHub. In fact, it's possible to see GitHub as a new killer app for the Internet--a "mini Web," as Preston-Werner describes it, a place where networked minds actually build things together.

"The network effect is awesome," Preston-Werner says, sitting in the situation room, another ironically themed chamber (this one has a red Batphone to nowhere, a massive table in burled veneer, Big Boy Executive Chairs, and LED signs with the time zones of various GitHub outposts). "There are standards now based on GitHub, so everybody can come in to a new project and immediately know how to get the code, how to contribute code, how to review the code, how to submit issues to the code base.... The more people do that, the stronger the effects and the gains from having a uniform, well-known, standardized system. And that's happening really, really rapidly."

That network effect gets reinforced in numerous ways. For example, a developer on GitHub acquires a social reputation, and that reputation becomes a way to find new, paying work; the network's role as a placement service helps it to grow still larger. The truly badass potential of GitHub, though, is that it isn't only a force multiplier for producing code but also for the generation of ideas--and for the products created from those ideas. As Preston-Werner says, projects hosted on GitHub will increasingly be "not just code, but anything that involves working on files on a computer: books, hardware projects, schematics for circuit boards, legal documents--anything that ends up in a digital format." This is already happening on the site, including projects for books (several coding manuals, for example, are being written on GitHub--including one about GitHub), hardware (OpenRov has the hardware design, software, and circuit schematics for its underwater robots on GitHub), and government (the U.S. and U.K. governments both work on the site).

Wanstrath, who handed the CEO title over to Preston-Werner in June and is an absolute geyser of GitHub zeal, agrees that as more people pile into the service, a shift is taking place: "Now we are finding that it's not just about the code; it's about, 'Hey, I want to work on this with you.' That's really eye-opening to us and gets everyone here superexcited. Working with someone else is just an awesome part of being alive. Creating art, creating tools, creating documents, doing homework, anything--it's not limited to programming. I don't see why musicians wouldn't want to work this way, for example."

In other words, as GitHub gets bigger, its power becomes less about the platform itself than about the people on it. One day in the GitHub offices, I ran into David ten Have, a New Zealander (and an Inc. cover subject in 2009). Ten Have is founder and CEO of Ponoko, a company focused on developing "the tools to enable digital fabrication." That means a system that could, one day, given a disassembled MP3 player, spec out each component, relay those specs to a 3-D printer, and have the printer produce all the pieces required for assembly by a nearby robot. Ten Have says, "GitHub makes this easier and faster, because it has a platform that enables the collaboration and, most important, the social norms to encourage people to look at the world collaboratively. That is fundamentally why GitHub is important beyond software: Ethos and attitude are transferable--into lawmaking, product design, manufacturing, biology, chemistry, dance, music, moviemaking, books, cooking... The list goes on."

And on. Which suggests that GitHub has only begun to grow--as a business, as a tool for business, and as a cultural force. "It's this huge ricochet effect," Wanstrath says, nearly manic with optimism. "We are this thing that people can step on, like an elevator, and then go shooting into space."

There’s no question that different programming languages are useful for different projects — it’s hard to justify completing every single project that comes across your desk in the same language, unless you only know the one. But while it’s often a good idea to be able to code in different languages if you’re working on a wide variety of projects, it’s not clear if there’s a magic number of languages you should know.

One, if…

If you work on the same sorts of projects over and over again, you may not need to know more than one language — at least at an expert level. There are a lot of benefits that come with expert-level knowledge of a language (like being able to put together a new app overnight) and it’s hard to reach that level with a single language if you’re constantly switching between other options. On top of that, there are plenty of frameworks that can extend the capabilities of a given language. However, if you’re interested in building bigger projects on your own, you’re going to eventually need to pick up another language or two.

It’s probably better to preemptively pick up a new language now, so you have more opportunities to work with it before you really need it. The Pragmatic Programmer goes so far as to suggest that all programmers should learn a new language every year if they want to stay relevant. Whether or not you need to learn a new programming language every year is a question that you have to answer for yourself, but it certainly makes sense to continue your education as a programmer and make a habit of trying out new languages.

The Right Tool

When you’re running your own company, the number of programming languages you need to know goes up. That’s because you’re the person in charge, even if you’re working with other programmers. At the very least, you need to be able to identify the right tool for any job that comes up. You need to have the right tools for your domain — what languages you need differ dramatically. If you’re working on enterprise web apps, you need different tools than if you’re working on a personal mobile app.

For the broadest set of tools, there are some basic options. You have to know a lower level language (like Java, C or Go) and a higher level language (like Python, Ruby or PHP). That division will allow you to have at least one language to work with core servers and other lower-level tools that may need to interface directly with the operating system. It’s also important to pick up a higher level language that will help you with web development these days, along with a framework — even if you’re not building a web app, you’ll probably need a website or two. Think about what you’ll need in terms of platform-based languages as well: go deeper than thinking about the operating system and consider if there are particular devices you expect to work with.

Image by Flickr user Jon Smith