IE kernel performs pretty well on web pages, which results from its installation proportion on computers. But it can not control resources ideally.
For one thing, the resource management principle of IE kernel is not efficient enough, for another, different kinds of plugins based on IE kernel may lead to a incomplete release of resources.

TheWorld 3.0 has been improved and optimized a lot in memory release. Especially under multi-process mode and mixed mode, pages are disposed in different processes. With features of multiple processes, procedures quit when web pages get closed and resources occupied by web pages will be released completely. Consequently, the problem that memory usage rises can be resolved drastically.