The OODBMS/DBMS ODABA is an terminology-oriented database management system (TODBMS) on a high conceptual level. This is an extension of the ODBMS concept according to ODMG 3. It provides a number of enhanced features based on natural language analysis. Beside the database kernel, a number of tools are provided for database design, documentation, and fast development. ODABA provides a powerful interface (C++, .NET) and an ODABA Script Interface (OSI), a C++/JAVA like scripting language, which provides easy access to the database.
MariaDB is a database server that offers drop-in replacement functionality for MySQL. It is built by some of the original authors of MySQL, with assistance from the broader community. In addition to the core functionality of MySQL, it offers a rich set of feature enhancements including alternate storage engines, server optimizations, and patches.
HailDB is a relational database in shared library form that can be embedded into applications. It is not a SQL database, although you can use this library as the storage backend for a SQL database. It features a clean and simple API and is a continuation of the Embedded InnoDB project. With the addition of the HailDB plugin to Drizzle, you get a full SQL interface.
Infobright Community Edition (ICE) is an analytic database built on MySQL, designed to deliver very fast query response against large data volumes. It is a self-tuning, columnar database that eliminates the need to create or maintain indexes, partition data, or perform other administrative tasks.
DeveelDB is an embedded SQL database management system for .NET, implementing all the features of the SQL92 specifications (transactions, triggers, procedures, functions, etc.). The aim is to provide .NET and Mono developers with a fully functional, powerful, and embeddable database system that can be used in several contexts, managing small to large amounts of data.
hamsterdb Transactional Storage is an ANSI-C implementation of a key/value database engine. It has a lock-free architecture, thus supporting an arbitrary number of long-running transactions and resolves transaction conflicts in memory without accessing the disk. hamsterdb uses logical, idempotent logging for recovery. It is thread-safe and concurrent, moving performance intensive operations to the background. Every hamsterdb handle can be used from arbitrary threads.
BlackRay is a relational database system designed to offer performance features commonly associated with search engines. It offers SQL support and sophisticated operational and management features. Load-balancing and operational stability by means of N+1 redundance are included. BlackRay is called a "Data Engine" since it combines traditional, relational database features and SQL with the power and flexibility of search engines. It is a true hybrid, offering transaction support, data-versioned snapshots, and sophisticated function-based indices. Wildcards, phonetic, and fuzzy logic searches are supported, as well. BlackRay supports a subset of the SQL92 standard and provides JDBC/ODBC/native driver options via the PostgreSQL protocol, in addition to an API based query option. The project is released under the GPLv2, with some drivers available under BSD-style licenses. Commercial support contracts are available as well.
PBL (The Program Base Library) is a C library of array/linked list, hash/tree set, and key file functions that can be used in a C or C++ project. It is highly portable and compiles warning-free on Linux gcc, Windows Cygwin gcc, Mac OS X, and Windows Microsoft Visual C++ 2008 Express Edition.