Adobe's Display PostScript NX facility [1] is a render service based on the PostScript rendering model. The NX facility provides transparent support for the Display PostScript Extension to X.
The primary purpose of Adobe's render server is to make up for X servers that lack direct support for the Display PostScript extension. This is in contrast to the primary purpose of GLR which is to provide access to high-performance 3D graphics hardware in a way that amortizes the cost of such hardware across multiple users. GLR can be used to obtain both better functionality (high-end features not available on low-end workstations) and improved performance.
Because GLR uses OpenGL (a pixel-oriented, interactive 3D oriented rendering model) and the NX facility uses PostScript (a resolution-independent 2D oriented rendering model), these render services address different needs.