The result of the latest works on the OPT source code is complete opt.class.php file which contains (as some of the readers may know) the main parser class. I must admit that this file was more demanding that the compiler. In the second case we can afford with quite a lot. Just an idea for the algorithm and prediction if and how it will influence the rest of the code. In the case of the main class, we must pay attention to the performance. It must contain everything that is run permanently and it must be fast and small. But the number of features is getting bigger and bigger.