Dataphor - A free application development platform streamlining the design, development and maintenance of software applications. Duro - A copylefted C library. Rel - An in-progress copylefted flavour of Tutorial D implemented in Java. MighTyD - A prototype for demo purposes, the first implementation of the temporal database model devised by Lorentzos, Darwen and Date. Uses Tutorial D and PostgreSQL, being compliant with The Third Manifesto. Dee - A truly relational language in Python. In development, early release available to gain feedback. Muldis Rosetta - Reference implementation of Muldis D, a programming language with fully integrated database functionality, that understands OOP and implements all of the relational operators, providing all the features of The Third Manifesto. SIRA_PRISE - An effort started by Erwin Smout to build a usable TRDBMS. Tcl Relational Algebra Library - A C-based extension of the TCL language implementing relational algebra. G-Exec2 - A planned reimplementation of one of the first relational systems, the British G-Exec from the 1970s, based on the open world assumption Raquel Database System - A Third Manifesto‐compliant RDBMS from Northumbria University, England. Free software. Ingres Project D - A research project that will provide a native implementation in Ingres of the Tutorial D language. IBM Web Relational Blocks - A visual language for constructing enterprise applications: relations are the only data-type which flows between components, and uses relational algebra A.