some modern real-time software renderers manage to combine a broad feature set and reasonable performance (for a software renderer), by making use of specialized dynamic compilation and advanced instruction set extensions like SSE. Although nowadays the dominance of hardware rendering over software rendering is undisputed because of unparalleled performance, features, and continuing innovation, some believe that CPUs and GPUs will converge one way or another and the line between software and hardware rendering will fade. Software fallback For various reasons such as hardware failure, broken drivers, emulation, quality assurance, software programming, hardware design, and hardware limitations, it is sometimes useful to let the CPU assume some or all functions in a graphics pipeline. As a result, there are a number of general-purpose software packages capable of replacing or augmenting an existing hardware graphical accelerator, including: RAD Game Tools' Pixomatic, sold as middleware intended for static linking inside D3D 7–9 client software. SwiftShader, a library sold as middleware intended for bundling with D3D9 & OpenGL ES 2 client software. The swrast, softpipe, & LLVMpipe renderers inside Mesa work as a shim at the system level to emulate an OpenGL 1.4–3.2 hardware device. WARP, provided since Windows Vista by Microsoft, which works at the system level to provide fast D3D 9.1 and above emulation. This is in addition to the extremely slow software-based reference rasterizer Microsoft has always provided to developers. The Apple software renderer in CGL, provided in Mac OS X by Apple, which works at the system level to provide fast OpenGL 1.1–4.1 emulation. OpenGL will use software rendering in case if a function is not supported by a graphics card. Pre-rendering Contrary to real-time rendering, performance is only of second priority with pre-rendering. It is used mainly in the film industry to create high-quality renderings of lifelike scenes. Many special effects in today's movies are entirely or partially created by computer graphics. For example, the character of Gollum in the Peter Jackson The Lord of the Rings films is completely computer-generated imagery (CGI). Also for animation movies, CGI is gaining popularity. Most notably Pixar has produced a series of movies such as Toy Story and Finding Nemo, and the Blender Foundation the world's first open movie Elephants Dream. Because of the need for very high-quality and diversity of effects, offline rendering requires a lot of flexibility. Even though commercial real-time graphics hardware is becoming higher in quality and more