MDB Tools is a suite of libraries and programs to facilitate the use of Microsoft Access databases, also known as Jet databases after the Microsoft's Jet Database Engine or as MDB databases after the .mdb extension used by the file containing the database.
MDB Toolsis open source software (also known as free software if you prefer) which means source code is provided under a license which allows you as a user to modify and redistribute the software. In particular, the libraries that come with MDB Tools are licensed under the Gnu LGPL (Lesser General Public License) and the utility programs, graphical interface, and miscellania are licensed under the Gnu GPL (General Public License). More information about these licenses can be found in the COPYING.LIB and COPYING files distributed with MDB Tools or from the Gnu site.