Open source software is much better at adhering to open standards than proprietary software is. If you value interoperability with other businesses, computers and users, and don't want to be limited by proprietary data formats, open source software is definitely the way to go.
With closed source software, you have nothing but the vendor's claims telling you that they're keeping the software secure and adhering to standards, for example. It's basically a leap of faith. The visibility of the code behind open source software, however, means you can see for yourself and be confident.
8. Support Options
Open source software is generally free, and so is a world of support through the vibrant communities surrounding each piece of software. Most every Linux distribution, for instance, has an online community with excellent documentation, forums, mailing lists, forges, wikis, newsgroups and even live support chat.
For businesses that want extra assurance, there are now paid support options on most open source packages at prices that still fall far below what most proprietary vendors will charge. Providers of commercial support for open source software tend to be more responsive, too, since support is where their revenue is focused.
Between the purchase price of the software itself, the exorbitant cost of mandatory virus protection, support charges, ongoing upgrade expenses and the costs associated with being locked in, proprietary software takes more out of your business than you probably even realize. And for what? You can get better quality at a fraction of the price.
10. Try Before You Buy
If you're considering using open source software, it will typically cost you nothing to try it out first. This is partly due to the software's free price, and partly due to the existence of LiveCDs and Live USBs for many Linux distributions, for example. No commitment required until you're sure.
None of this is to say, of course, that your business should necessarily use open source software for everything. But with all the many benefits it holds, you'd be remiss not to consider it seriously.
Follow Katherine Noyes on Twitter: @Noyesk.