Processor: Dual Core (for better performance) about 1.0 GHz
Graphic card: OpenGL 1.5 compatible
System: at least Windows XP (not tested on earlier versions)
Development:

In-Game console (Quake 3 like :P)
Game logic is written in LuaScript
Over 150+ engine functions exported to LuaScript
Config 'INI' files holds configuration of all important elements to tune up your game
Profile System:

Each player can have own profile
Each game has it's own data section
Structure of game section is totaly up to developer
All achievements are defined in definition file
Graphics:

Low level requirements (OpenGL 1.5)
Anglecode Bitmap Fonts with Unicode support
Software Renderer in C++ SDK version ^^
GUI System:

Multiple Windows support
Skins support
Transparency
Windows definition file for creating windows and controls
LiveData Manager:

Data is loaded in background on seperate thread
Reloads textures when file changed
Release data when not used for 10 minutes and load it again when needed
Sound:

3D sound achieved with OpenAL library
Many useful functions to tune up sound sources
No need to load sounds. Just call 'Play' and engine will do the rest.
Instant response thanks to buffering sounds in background on seperate thread
Networking (currently DISABLED):

Networking is based on Non-Blocking Socket
No "Hard" limit for connected clients
Packets are compressed and crypted
Automated network managment
Easy to develop by using two special scripts for recived packets
Object Manager and Physics (currently DISABLED):

2D Physics achieved with Box2D library
Physics module works on seperate thread. Rendering and physics are independent. So many physic objects not equals low FPS
Each object has indepented animation
Each animation set can have unlimited textures, animatinons and frames
Both objects static and dynamic can be moved by applying forces
Materials assigned to objects define's density, friction, and restitution
Debug Mode including: Collision Boxes, Center of each shape, mass and whole body.
Custom polygon shapes
Each body can have unlimited shapes
Each shape has indepented animation
Other features:

Fully customized by scripts and config files
No need to compile any code
Dynamic language change support
Engine supports modification feature similar to Quake Mods. Each "mod" is placed in diffrent folder and have own script and config files
DLL dependency free
No need to install any kind of software. Just download and run.
Free for non-commercial