The following is a list of important facts about the Professional Edition.

The price is normally $800 (USD) per user.

The full source code for the engine, tools, and demo game is included.

You receive all future updates at no additional cost, forever.

You are allowed to receive any amount of funding from a publisher. (The Standard Edition is limited to $100,000.)

Two support incidents per year are included at no additional cost. (Each support incident normally costs $100.)

Support incidents are allowed to be used for minor feature requests. (This is not available in other editions of the engine.)

The unpacked art resources for games made by Terathon Software are provided as examples.

You receive free copies of all games made by Terathon Software.

A copy of The Beginner's Guide to the C4 Engine is included at no additional cost (including updates).

You are given access to early alpha versions of the engine. (The Standard Edition only includes beta access.)

You receive a free C4 Engine poster and T-shirt. (Not available in all countries.)

Thousands of independent developers already use the C4 Engine for their game projects, and they've had great things to say about their experiences. Read their reviews on DevMaster.net.

Hands down C4 has the best support I have ever seen for any engine.

An absolute knockout engine with the power of a AAA engine at the cost of an indie engine. You can't go wrong.

The structure of the source code is the best I've ever seen. Clean, well presented, and clearly very well thought out.

The rendering is superb, and the engine is chock full of high performance, high-powered graphics capabilities.

High-quality features keep making their way into the core, and those features tend to be perfectly solid, sensible, and ready to be put to productive use from the very first time they appear. No half-baked ad hoc stuff.