You can link the library either statically or dynamically with your application. It has been tested on Win32, Linux and Solaris. The library can be used freely for applications that are free. For other uses, read the license available at the website. The system is free for both personal and commercial use.
Source code is available under a maintainence contract.
You cannot however redistribute the DLL but you can always direct your customers to the website. This SQL server currently provides a subset of the ANSI SQL language. A Win32 port as well as an ODBC driver is currently under development. There is a version for Linux, SCO, FreeBSD, Solaris, etc. According to its web site, the GNU SQL Server is a free relational database management system that supports the full SQL89 language and some of the SQL92 extensions.