Vieka eSQL is a free (for personal and non-profit use only) portable and powerful embedded relational SQL database server for Windows Mobile Pocket PC and Smartphone devices based on the SQLite database engine. You can create, edit and query database records from your mobile device just as you would from a desktop computer. It is also possible to fetch information from the eSQL database from a mobile application installed on the device.

Features of eSQL Mobile include:

-Implements most of SQL92 standard, such as multiple tables, multiple indexes, transactions with atomic commit/ rollback, subqueries, compound queries, views, triggers.
-Support for in-memory database.
-Support database size up to 2 terabytes.
-Compression for compacting database.
-AES 256-bit encryption for securing data.
-Native C/C++ or standard ODBC API is simple and easy to use.
-eSQL.Net data provider for Microsoft .Net integration and rapid application development.
-A cross-platform graphical database manager can be used to administer an eSQL database.
-An interactive SQL command line tool is provided as an example of how to use eSQL in your application.

Note:Some of the above mentioned features are available in the Windows version of eSQL from Vieka which can be downloaded here

Download Links:
Windows Mobile Pocket PC Link
Windows Mobile Smartphone Link

The complete package including eSQL programs, eSQL.Net, eSQL samples, eSQL libraries for Windows and Windows Mobile, including both Pocket PC and Smartphone can be download here

(Requires Microsoft Compact .NET Framework 2.0)