McObject's eXtremeDB is an in-memory embedded database. Several versions of the product are currently available; including the Standard Version, High Availability Edition, Transaction Logging Edition, eXtremeDB-64 (a 64-bit version), and the new eXtremeDB Kernel Mode (KM), a version designed for deployment in the operating system kernel.

Features of eXtremeDB include:

- Task scheduling, employing a synchronization mechanism that, according to the vendor, minimizes context switches while using fewer CPU cycles to resolve resource contention.

- NVRAM support presents a recovery option for an in-memory database. eXtremeDB enables a process to reconnect to the NVRAM-hosted database, initiate any needed cleanup, and then resume normal operation after the system reboots.

- eXtremeDB High Availability version adds support for "1-safe" or asynchronous replication. In 1-safe replication, a database transaction is committed on the primary node without waiting for updates to propagate to replica nodes, (eXtremeDB already supported 2-safe or synchronous replication).

- eXtremeDB's database browser utility enables a user to browse and edit a database's contents during development, for testing and verification.

- Remote Access Interface. eXtremeDB will generate an interface enabling programs to read from and write to eXtremeDB from different machines on a network.

- Unicode. eXtremeDB's support for Unicode enables use of a range of character sets (such as many Asian alphabets).

Visit the vendor's Web site for specific details pertaining to the differences between versions.

- eXtremeSQL is an SQL interface that provides a tool for eXtremeDB-based embedded systems to share data with corporate applications such as billing, shipping, customer relationship management, and enterprise databases.

eXtremeSQL features and capabilities include:

- Implements most of the ANSI SQL-89 specification for INSERT, UPDATE, DELETE and SELECT statements

- Implements eXtremeDB-specific extensions including support for structures, arrays, vectors, and optimization of queries on classes with object identifier relationships

- Fully interoperable with eXtremeDB Standard Edition, High Availability Edition, and Transaction Logging Edition

- Includes an interactive SQL program, eXQL, that can test SQL statements or serve as an example of a full eXtremeSQL implementation. eXQL also works as a batch processing utility by redirecting input from a text file containing eXtremeSQL statements

- eXtremeSQL is embedded in the application, not deployed as a separate process