txtSQL (pronounced "text-sequel") is an object-oriented (OOP) flat-file database management system written in PHP. Working on ordinary text files with increased file-security, it offers support for a small subset of SQL and is extremely efficient in terms of execution time. txtSQL utilizes a file system similar to that of MySQL by employing the concept of tables and databases. Furthermore, it does not require any outside plugins just so that txtSQL can operate. There are two levels of operation for developmental purposes; a low-level implementation and a high-level implementation that supports SQL. txtSQL is an open source project licensed under the GNU General Public License (GPL).