What are the most popular database management systems? DB-Engines Ranking provides a list that's updated monthly. You can look at the complete ranking or filter by types like Relational DBMS, Key-value stores, Document stores, Graph DBMS, RDF stores, Search engines, and more.
For a ranked list of popular databases, check out the DB-Engines Ranking page on the DB-Engines site, a knowledge base of relational and NoSQL database management systems.
Most Popular RDF Stores as of April 2017
Following, for example, is a list of popular RDF Stores as calculated in April 2017.
Number of mentions on websites, measured as number of results in search engines queries on Google, Bing and Yandex (searching for <system name> together with the term database, e.g. "Oracle" and "database").
General interest in the system, as determined by the frequency of searches in Google Trends.
Frequency of technical discussions about the system, as determined by the number of related questions and the number of interested users on Stack Overflow and DBA Stack Exchange.
Number of job offers, in which the system is mentioned on leading job search engines Indeed and Simply Hired.
Number of profiles in professional networks, in which the system is mentioned in popular professional networks LinkedIn and Upwork.
Relevance in social networks, as per a count of the number of Twitter tweets, in which the system is mentioned.