The Theory of C4.5 Algorithm Improvement
Quinlan went on to create C5.0 and See5 (C5.0 for Unix/Linux See5 for Windows) which he markets commercially. C5.0 offers a number of improvements on C4.5. Some of these are:
Speed - C5.0 is significantly faster than C4.5 (several orders of magnitude)
Memory usage - C5.0 is more memory efficient than C4.5