The Building Architect Tool (BAT) is a suite of tools developed for producing custom buildings. The suite consists of three applications: The Building Architect game pack for Gmax, which enabled users to render Gmax models into "SimCity 4" sprites or props to be imported into the LE; an updated version of the LE; and the standalone Plug-in Manager, which enables users to modify simulation properties for new lots. Several modified versions have been released that have, in effect, served as bug fixes for various problems that had not been discovered before the initial release. First released in February 2004, it enabled the modding community to produce custom buildings and props for "SC4". "SimCity 4" Building Architect Tool is similar in function to "SimCity 3000" Building Architect Tool and "SimCity 2000" Urban Renewal Kit; however, previous programs of this kind were created from scratch by Maxis and used completely different interfaces. The "SC4" BAT required a third-party application (Gmax) to function and was never bundled with "SC4" or the "Rush Hour" expansion pack, as "SimCity 3000 Unlimited" had with its own BAT.