Free database engine software for windows

H2 is an SQL database engine written in Java (but also available as a native binary). JDBC and ODBC APIs are supported. Embedded and server modes are available. A Web console application is included. Clustering is supported.H2 Database Engine is a web based java database engine.
Main features:
- Fast database engine
- Free, source code is included
- Supports standard SQL
- Written in Java
- Disk based or in-memory databases
- Browser base Console application
- JDBC API
- Limited ODBC support
- Embedded and client/server (network) mode
- High availablility support (clustering / failover)
- Wide range of data types including large objects (BLOB/CLOB)
- Strong security features (SSL, users, roles, encrypted files)
- Multiple connections, table level locking
- Cost based optimizer, using a genetic algorithm for complex queries
- Transaction support (serializable transaction isolation)
- Zero-administration, automatic recovery
- Large resultset, external sorting
- Scrollable and updatable resultset support
- Read only views and inline views
- Inner and outer joins, subqueries
- Many functions already built-in
- Triggers and Java functions / stored procedures
- Referential integrity / foreign key constraints with cascade, check constraints
- Multiple schema support
- Compatibility modes for HSQLDB, MySQL and PostgreSQL
- Sequence and autoincrement columns
- Well tested (high code coverage, randomized stress tests)
- Small footprint (smaller than 1 MB)
- Uses a small number of database files
- Can be compiled to native code using GCJ
- Primary keys, multiple index types (b-tree, linear hash, tree, hash)
- ORDER BY, GROUP BY, HAVING, UNION, LIMIT
- Information Schema
- Multiple connections
- Collation support
- EXPLAIN PLAN support
- The database can generate SQL script files
- Support for linked tables, and a built-in virtual range table
- Automatic re-compilation of prepared statements
- Sophisticated trace options
- Low memory requirements
- Easy to understand exception messages
- Standard handling of NULL values
- Multilanguage console application (at this time, English and German)

Matrix Embeddable Database Engine 0.3b is created to be a useful Java embeddable database engine which is aimed at Java applications requiring fast and seamless persistence and retrieval of objects.

Major Features:

1. Class is the Schema: Realtime Class registration and data persistence
2. Multi-Thread Single-VM: Matrix engine can be instantiated in multiple threads from a single VM
3. Object Locking: Runtime locking of Matrix persist-able objects maintaining transactional sanctity across all instantiated engines
4. Transaction Atomicity: Simple single-line set/get methods for complex DML functions
5. Fail-safe: Primary application thread remains safe by trapping exceptions
6. Where-clause: Object querying by where-clause like text
7. In-memory Indexing: Unique in-memory index technology
8. Cursors: Bidirectional parse-able cursors
9. Encryption: Database internals are encrypted
10. Zero Maintenance: Auto space management / auto archiving
11. Logging: Auto-Logging of database activities at two levels
12. Minimally Intrusive Interface: Classes intended for Matrix persistence need to implement a simple interface only.