Some of the key features of the ÜberTools technology are:

TIKI Model System

Built-in scripting on a frame-by-frame basis
Client-side and server-side scripting reduces net-transmission of effects
4-part character state system for independent control over eyes, head, torso, and leg orientations
Low memory footprint Skeletal Animation System
Bone support for attaching other models or effects
Variable playback rates for animation
Movement deltas determined from animation eliminates skating of actors
Support for movement driven animation (player speed controls rate of animation)
Improved lighting model correctly lights models from light sources around him rather than at his feet
Real time interpreted player state system.
Single skin weighted mesh (deformable meshes)

Babble Dialog System

Allows models to lip-sync to audio files
Coordinated dialog system allows "conversations" between actors
Dialog system stores variables for characters to react to you based on variables set globally or in level scripts.

Dynamic Music System

In-game Scripted Camera System

Spline-based path following for dramatic camera movement
In-game editor allows developer to instantly view and modify the camera's actions
Full control of camera available from script allows cuts between multiple cameras
Paths generated in-game can be exported to separate files, or re-imported into game map as object paths
Camera paths are saved out as external .cam files and can be reloaded by the game script or by the in-game interface for modification and playback

Morpheus Scripting System

Simple syntax allows non-programmers to quickly write scripts
Easily expandable command set
Gives control over ANY object in the game
Multi-threaded
Persistent and temporary variables
Conditional statements allows complex game and object logic
Developer can script the movement of objects, character AI, and cameras
Allows complex control of game flow over multiple levels
Entirely text-file based, so testing changes can be done by simply reloading the map

Fully scriptable
State based system allows characters to react in a variety of ways to different events
Developer can override default behavior of any character via script for special events
Programmers can easily extend the set of complex behaviors through C++ based Behavior objects
Built-in path following allows characters to traverse map in an intelligent manner
Built-in behaviors for using cover and hiding
Characters can react to sound, sight, and triggered events
Weapon system allows characters to use any weapon in the game
Node based path following.

Levels

Quake III Team Arena Terrain technology implemented with greater map extents than any Quake engine game has seen before.
Terrain technology extended upon with PVS dependant terrain rendering.
Dynamic lighting added back into the Quake 3 engine, allowing for dynamic modification of intensity, and day to night transitions.
Optimized use of light maps and vertex lighting.

Miles Sound System Integration

Supports software and hardware accelerated 3D sound mixing
.wav playback for sounds
.mp3 playback for music
DSP effects
In-Game tool used by sound engineer to place music triggers, sound emitters, and reverb triggers.
Standardized interface for working with a variety of APIs (DirectSound, Intel, MMX, Auriel)

Ghost Particle System

Allows stunning weapon effects and eye candy
Script-definable allows development of a variety of effects without programmer involvement
Emitters can be attached to bones on models-allows blood spurts, muzzle flashes, etc.
In-game Emitter editor allows developer to instantly view and modify the Emitter's properties
Complex particle movements can be achieved by animating invisible tags within models

Extended Shader Support

Allows conditional use of multitexture effects (for cards that don't support multitexture)
Plug-in to QERadient offers nice intuitive interface for editing shaders
Extended alpha generating commands such as dot and 1-dot allow view dependent effects
Extended RGB generating commands gives entity based color modulation of texture passes.
Indexing of shaders moved off-line to give faster map load times

Lens Flare System

Script-based definition of flares gives artist control over lens and sun effects.

Localization

Support for localization of all text based dialog and subtitles with extended fonts.

Far Clipping Plane

Specify color, distance, and culling options in the level or dynamically at game time.
Levels can be built with farplane culling instead of Quake style visibility
Farplane culls world geometry
Farplane speed optimizations that render limited passes on models drawn in the farplan

Sky Portals

LOD System

As model gets farther away, few polys are drawn
Non-drawn vertices don't get transformed, saving on CPU time
Seamless models can reduce down to 0 polys
Seamed models reduce less, but are supported (many systems do not provide ANY support for seamed models)
LOD rate can be controlled per-model, allowing some models to reduce at closer or farther distances
User can reduce detail globally to get faster frame rates

Improved QERadient

Improved clipper
Variable lightmap density set per texture or in a global value by the tools
TIKI models visible in editor
Control over level of tessellation of curve meshes
Area based lights
In Editor lighting preview
Surface attributes allow in-game distinction of woods, metals, dirt, etc, for sounds and player interaction
Improved texture alignment tools
ShaderED plug-in allowing for easy creation of shaders with a windows interface

User Interface

In-game menu's and in-game development tools are created in an external UI menu creation program
In-game menu's can slide in from any direction at any speed.
In-game menus have unique specifiable alpha, shader, font, texture, alignment, and variables per widget.
In-game version of "notepad." Used for editing scripts, tikis, shaders, or just about anything else in-game without exiting.