Firebird 3 is focused on performance and security. Many changes were necessary to accomplish this, and some of those changes may confuse some users coming from older versions. The Migration Guide to Firebird 3 eBook came to help existing users to understand those changes, and migrate their servers/databases to Firebird 3, avoiding headaches and in the shortest time possible. More information about the English version of the eBook can be seen here.
For Brazilians, there is a version in Portuguese here.

Firebird Project is happy to announce general availability of Firebird 3.0 — the latest major release of the Firebird relational database.

The primary goals for Firebird 3.0 were to unify the server architecture and to improve support for SMP and multiple-core hardware platforms. Parallel objectives were to improve threading of engine processes and the options for sharing page cache across thread and connection boundaries.

Alongside these aims came new strategies to improve performance, query optimization, monitoring and scalability and to address the demand for more security options. A number of popular features were introduced into the SQL language, including the long-awaited support for the Boolean data type and the associated logical predications.

Read the Press Release for more information. Please refer to the Release Notes for the full list of changes. Binary kits for Windows and Linux on both 32-bit and 64-bit platforms are immediately available for download. MacOS X and other platforms will follow.