Community is the lifeblood of an open-source project, and so measuring the size and vitality of a given open-source community is critical when making the decision to adopt a particular project. After all, the greater the number of developers contributing to a project and the greater the number of users putting the software through its paces, the safer your investment will be in that open-source project.
Unfortunately, there's no One True Way to measure open-source community. In fact, there are many ways to measure community around an open-source project, each with its own strengths and shortcomings. Still, there are reasonable metrics to approximate community around an open-source project.
Of the various options, one of the most robust is job trend data. Here, new data released by 451 Research makes it clear that MongoDB is ...way-ahead of all the othersÃ¢â‚¬Â_[and] outpacing many of its rivals,â€œ in terms of jobs created and posted.
451 Research pulls this jobs data from LinkedIn. Indeed.com, however, comes to the same conclusion based on different jobs sources:
Job trends are not the only way to measure the vibrancy of an open-source project, of course. Acquia, for example, has its own approach to measuring the strength of the Drupal community. And it's pretty telling that within hours of announcing that 10gen would be offering free online MongoDB training, thousands of people signed up, with thousands more joining every day since.
But job trends may be an even better indicator, because they indicate real dollars being spent on real people to build real applications.
Early in the commercial lifespan of open source, we used downloads to track open-source community success. There were a variety of problems with this approach, not the least reason being the dispersal of open-source projects from Sourceforge to a number of new competitors, most recently GitHub.
Other means have arisen, as 10gen President Max Schireson describes in a 2011 blog post. Of the different means Schireson outlines (forum posts, Google Insights, job postings), the job postings may actually be the clearest indication of serious community traction. Marten Mickos, current CEO of Eucalyptus Systems and former CEO of MySQL, used to argue that in a given open-source community, for every 1,000 users there were maybe 100 developers contributing to the project and one paying customer.
Job trends data are a great way to cut across these categories and measure real interest in an open-source project, minus the noise that Google Insights offers or the gamesmanship that downloads affords. Perfect? No. But in the absence of perfection jobs data are a solid way to measure the size and seriousness of community around an open-source project.