HTSQL forms the basis of RexDB ( https://rexdb.org https://rexdb.org https://bitbucket.org/rexdb/ https://bitbucket.org/rexdb/ https://dist.rexdb.org/packages/

HTSQL forms the basis of RexDB ( https://rexdb.org https://rexdb.org https://bitbucket.org/rexdb/ https://bitbucket.org/rexdb/ https://dist.rexdb.org/packages/ https://dist.rexdb.org/packages/ ), which is a very active project. That said, HTSQL is not being commercially supported apart from Prometheus Research's RexDB installations. HTSQL itself is actively maintained but will not see any significant new features. Even so, HTSQL is quite productive to use, will be supported for quite some time for our products and clients, and it's used extensively internally here at Prometheus Research. The next generation this effort is called Rabbit (MIT licensed) and we will announce it sometime this year or early next year. The RexDB API for Rabbit will be called rex.query (https://bitbucket.org/rexdb/rex.query https://bitbucket.org/rexdb/rex.query) and, till Rabbit is fully developed enough to replace HTSQL, rex.query be targeting the HTSQL/PostgreSQL backend.