xml2sql is a collection of Perl script to convert XML files into SQL scripts for creating tables in a database. The generated SQL scripts are commented with the descriptions you provide in your XML, so it it easy to figure out what does what. xml2sql does no validation of your XML files.
twz1jdbcForMysql (aka tjFM) is a type 4 JDBC driver for TcX's MySQL database. It has numerous initialization options settable by URL parameter, passed Properties or a properties file (for applications). It can cache query results to memory (default), disk (applications only) or not cache at all at the user's option. It handles insertion (through PreparedStatement) and retrieval of binary objects (blobs) and is delivered with source.
Orac is a GUI tool for Database Administrators written in Perl, Tk, and DBI. It organizes many useful DBA scripts into a nice graphical interface, for collecting statistics on your database, or diagnosing problems. It currently supports Oracle, Sybase, and Informix. Richard Sutherland's DDL::Oracle Perl module has been integrated with the current version for the Oracle side of things, greatly improving the Oracle developer options on the program.
ODBC Socket Server is a database access toolkit that exposes Windows NT ODBC data sources via an XML-based TCP/IP interface. The base distribution includes a 32-bit multi-threaded Windows NT Service and clients written using COM (Windows C++), Perl, PHP, Python, and C++ (Linux). Most clients include source code and everything is very well documented in an easy to read PDF manual.