The V-Ray rendering system has a rich set of features; we have listed some of the major ones here. For a full list of features and capabilities visit the V-Ray documentation. Please be aware that every features is subject to change without prior notice.

Core architecture
Multi-platform object-oriented API
Fully multithreaded core
Unified sampling system based on Schlick sampling
Distributed rendering
Efficient shading system specifically optimized for ray-tracing
Modular architecture - many components of the system can be replaced with custom ones

Geometry
Efficient geometry handling
True instance rendering
On-demand dynamic geometry creation
On-demand geometry loading from disk files
Displacement mapping
Catmull-Clark and Loop subdivision surfaces
Extensible with custom geometric primitives through the V-Ray SDK

Image sampling
Three different image sampling methods
Full-scene antialiasing
Progressive path tracing
Support for additional render elements (diffuse, reflection, GI etc)
Advanced color (tone) mapping controls
Extensible with custom image samplers through the V-Ray SDK

Illumination
Physically accurate full global illumination solutions
Different GI algorithms: path tracing, irradiance cache, photon maps, light cache
Reusable GI solutions for accelerated rendering of walk-through animations and animations with dynamic objects
Physically accurate area lights
Efficient illumination from HDR environments
Procedural sun & sky models
Extensible with custom lights through the V-Ray SDK
IES photometric lights

Shaders
Physically plausible materials
Blurry reflections/refractions
Accurate hilights
Sub-surface scattering
Support for efficient material layering
Extensible with custom shaders through the V-Ray SDK

Camera effects
Depth-of-field with bokeh effects
Accurate motion blur
Physical camera model
Extensible with custom cameras through the V-Ray SDK

Extras
Toon effect
Fur generator/raytracer
Extended matte/shadow capabilities
Support for Render-to-Texture mode of 3ds Max
VRaySphereFade to isolate only specific portions of the scene for compositing

Frame buffer
V-Ray specific frame buffer with integrated color corrections and display of multiple rendering elements
Direct rendering to disk for extremely large images, either as OpenEXR files or as .vrimg files