even database services. [Workplace OS's lead architect Paul Giangarra] believes that locating such application-oriented services close to the microkernel will improve their efficiency by reducing the number of function calls and enabling the service to integrate its own device drivers." This layer contains the file systems, the scheduler, network services, and security services. IBM first attempted a device driver model completely based in userspace to maximize its dynamic configuration, but later found the need to blend it between userspace and kernelspace, while keeping as much as possible in userspace. The Adaptive Driver Architecture (ADD) was designed for the creation of layered device drivers, which are easily portable to other hardware and operating system platforms beyond Workplace OS, and which consist of about 5000-8000 lines of device-specific code each. Some shared services are common only to select personalities, such as MMPM serving multimedia only to Windows 3.1 and OS/2 personalities, and which is alien or redundant to other markets. Atop the shared services, another layer of userspace servers called personalities provide DOS, Windows, OS/2 (Workplace OS/2), and UNIX (WPIX) environments. The further hope was to support OS/400, AIX, Taligent OS, and MacOS personalities. Personalities provide environment subsystems to applications. Any one personality can be made dominant for a given version of the OS, providing the desktop user with a single GUI environment to accommodate the secondary personalities. In 1993, IBM intended one release version to be based upon the OS/2 Workplace Shell and another to be based upon the UNIX Common Desktop Environment (CDE). IBM explained the branding: "Workplace OS is the codename for a collection of operating system components including, among others, the IBM Microkernel and the OS/2 personality. Workplace OS/2 is the specific codename for the OS/2 personality. Workplace OS/2 will operate with the IBM Microkernel and can be considered OS/2 for the PowerPC." For the 1995 final preview release, IBM continued, "When we stopped using the name 'Workplace' and started calling the product 'OS/2 for the PowerPC', you might have thought that the 'Workplace' was dead. But the 'Workplace' is far from dead. It has simply been renamed for prime time." Workplace OS/2 was intended to define the future of OS/2, as a 32-bit clean platform and free of internal legacy, with perfect compatibility for source code of OS/2 applications and drivers. IBM originally wanted to prove new development models on Workplace OS/2 and backport them into OS/2