ARBvertexprogram
ARBvertexprogram is a set of assembly-like instructions used in OpenGL for programming the vertex processing stage of the graphics pipeline. This allows developers to perform custom calculations on vertex data, such as transforming vertices, calculating lighting, and generating per-vertex attributes that can be passed to the fragment shader. It provides a lower-level control over vertex transformations compared to fixed-function pipeline operations.
These programs are written in a specific assembly language defined by the OpenGL ARB (Architecture Review Board).
The primary purpose of ARB vertex programs was to enable more sophisticated visual effects and optimizations