To decide whether a full-blown POS system is required, see Do You Need a Point-of-Sale System for Your Small Business?
Before listing some of the leading retail-specific software programs, it's important to note that as advanced as technology is, a software program is typically only as good as the person using it. Therefore, an elaborate system is useless if your employees struggle with it. The software system needs to be user-friendly, easily maintained, and provide excellent tech support. Of course, you should always have backups of your data and be able to shift to a good, old-fashioned manual sales process if necessary. There's nothing worse than having to shut down for the day because there is a glitch in your software program or your computer is down. In other words, do not let yourself become overly dependent on retail software.
All that being said, here are a few of the many retail software programs available: