Talk to an open source evangelist and chances are he or she will tell you that software developed using the open source model is the only way to go.\nThe benefits of open source software are many, varied and, by now, well-known. It's free to use. You can customize it as much as you want. Having many sets of eyes on the source code means security problems can be spotted quickly. Anyone can fix bugs; you're not reliant on a vendor. You're not locked in to proprietary standards. Finally, you're not left with an orphaned product if the vendor goes out of business or simply decides that the product is no longer profitable.\n[ Learn the 10 old-school IT principles that still rule and the 12 'best practices' IT should avoid at all costs. | Find out what your peers are up to with our 2019 State of the CIO report. | Get the latest insights by signing up for our CIO daily newsletter. ]\nHowever, the open-source evangelist probably won't tell you that, despite all these very real benefits, there are times when using closed-sourced, proprietary software actually makes far more business sense.\nHere are some of the circumstances when old-fashioned proprietary products are a better business choice than open source software.\n1. When It's Easier for Unskilled Users\nLinux has made a huge impact on the server market, but the same can't be said for the desktop market \u2014 and for good reason. Despite making strides in the last several years, it's still tricky for the uninitiated to use, and the user interfaces of the various distributions remain far inferior to those of Windows or Mac OS X.\nWhile Linux very well may be technically superior to these proprietary operating systems, its weaknesses mean that most users will find it more difficult and less appealing to work with. That means lower productivity, which will likely cost far more than purchasing a proprietary operating system with which your staff is familiar.\n2. When It's the De Facto Standard\nMost knowledge workers are familiar with, and use, Microsoft Word and Excel. Even though there are some excellent open source alternatives to Office, such as LibreOffice and Apache OpenOffice, they aren't identical in terms of functionality or user interface, performance, plugins and APIs for integration with third-party products. They are probably close enough as much as 90 percent of the time, but on rare occasions there's a risk that these differences will cause problems \u2014 especially when exchanging documents with suppliers or customers.\nIt also makes sense to use proprietary software in specialist fields where vendors are likely to have gone into universities and trained students on their software. "The software may not necessarily be better, but it may be selected by a university before an open source solution gets a big enough community around it," says Chris Mattman, an Apache Software Foundation member and a senior computer scientist at the NASA Jet Propulsion Laboratory.\n"When that happens, the students will then know the software better and be more productive with it," Mattman says. When the students then move into a business environment, it makes sense for them to continue with the software they are used to.\n3. When Proprietary Software Offers Better Support\nBusiness-class support is sometimes available for open source software, either from the company leading the project or a separate third-party. This isn't the case often, though \u2014 and that can be a problem, according to Tony Wasserman, professor of software management practice at Carnegie Mellon University.\n"Some customers prefer to have someone outside the company to call for product support on a 24\/7 basis and are willing to pay for a service level agreement that will provide a timely response," he says. "People often respond very quickly to queries posted on the forum pages of widely-used open source projects, but that's not the same thing as a guaranteed vendor response in response to a toll-free telephone call."\n4. When You Want Software as a Service\nCloud software is slightly different than conventional software. As a general rule, you don't get access to the source code, even if the hosted software is built entirely on open source software. That may not make the software proprietary, strictly speaking, but it doesn't give you all the benefits of open source. In that sense, the benefits of using the "pay for what you use" software as a service model may outweigh the disadvantage of not having access to the source code.\n5. When Proprietary Software Works Better With Your Hardware\nMany types of proprietary hardware require specialized drivers; these are often closed source and available only from the equipment manufacturer. Even when an open source driver exists, it may not be the best choice. "Open source developers may not be able to 'see' the hardware, so the proprietary driver may well work better," Mattman says.\n6. When Warranties and Liability Indemnity Matter\nSome open source software companies, such as Red Hat, are structured to look like proprietary software vendors. They accordingly offer warranties and liability indemnity for their products, just like proprietary vendors do. "These companies are exactly the same as proprietary software companies, except that they won't take you out to play golf," Wasserman says.\nFor every Red Hat, though, there are many open source projects that aren't backed by a commercial organization. While you may get warranties and liability from a third-party, in many cases you won't. If that doesn't suit you or your company's software procurement policies, then you're advised to find a proprietary vendor.\n7. When You Need a Vendor That Will Stick Around\nYes, there's no guarantee that a commercial software vendor will stick with a product if demand drops to such an extent that it's no longer profitable to develop it. The company itself may even go out of business. But if an open source project is small, there's also a danger that the person behind it may lose interest. If that happens, it may not be easy to find another open source developer to step in.\n(This may be more of an argument against small open source projects than an argument for proprietary software \u2014 but at least you can look into the books of large software companies and make an informed decision as to whether they're likely to be around in a few years to honor any commitments they give you.)\nDon't Be Too Dogmatic About Open Source Software\nThe lesson here: While open source software may often \u2014 and even usually \u2014 be a better choice than functionally similar proprietary offerings, it doesn't make sense to be too dogmatic about it.\n"As a practical matter, I think that many people would prefer to have everything open, especially in light of the recent revelation about the NSA spying on machines through USB chips," Wasserman says. At the same time, though, many of those who prefer open source will make exceptions when there are no practical alternatives \u2014 not to mention their use of Mac and iOS devices \u2026 "