As NoSQL takes root in the enterprise, it's becoming clear that developers will need to gain greater familiarity with both the concepts behind it, as well as the various products that support it.

The current series on Dr. Dobb's is a tutorial on MongoDB, the most popular of the NoSQL products. It has many worthy competitors, some of which are presented here in summary form, as a means to show a larger range of options and provide data for selecting the appropriate NoSQL products to evaluate for your needs.

(Note : There are many more options in this space, with new entrants coming to market all the time. The information here comes from many avenues: vendor websites, blogs, Wikipedia, and our own contacts with the vendors.)