Current Release
The current open-source release (0.9.3) of LucidDB is available for download. It is packed with advanced features; there are also some limitations you should be aware of:

• support for correlated subqueries is still under development (uncorrelated subqueries are now fully optimized via constant reduction)
• security features remain incomplete
• writers never block readers, but writers block other writers on the same table
• all transactions are autocommit
• any join condition is supported for LEFT/RIGHT OUTER JOIN, but FULL OUTER JOIN support is limited to equijoins
• one single database-wide auto-extend tablespace
• FOREIGN KEY and CHECK constraints are not supported
• a limited number of system views and management procedures are available
• collation is always case-sensitive
• no support for timezones and time intervals
• the only client API provided out-of-the-box is JDBC; however, integrations for other client/language environments are available
• external user-defined routines are written in Java

Planned for Follow-on Releases (Let us know if you're interested in contributing, either to projects listed here or items of your own.)

• out-of-the-box client support beyond JDBC (e.g. ODBC, DBI)
• complete subquery support
• tablespaces
• robust security
• optimizer improvements and executor performance enhancements, including parallelism
• more management views and functions
• collations, timezones, and time intervals
• SQL/J procedure support
• materialized views
• tighter Mondrian and J2EE integration
• more connectors (e.g. XLS via POI) and ETL functions

Eventually...

• SQL/OLAP
• user-level transactions
• FOREIGN KEY and CHECK constraints
• fully cost-based optimization
• user-defined types
• bulk write to external systems
• clustering (see the Firewater project)
• support for both row-store and column-store tables in the same database
• support for arbitrary FULL OUTER JOIN conditions

Maybe One Day...

• SQL/XML
• ...