This book sheds light on assessing written coherence of non-native English speaker writers and utilizing open-sourced in educational practice. The study presented in the book demonstrated the power of Centering Theory in assessing written coherence for non-native English speakers. When Centering Theory is extensively adopted in auto-summarizing and coherence research, it is less used for non-standard written English. The book proposes that the theory can be effectively used in detecting coherence breakdowns in Chinese English learners. Furthermore, from the book it is interesting to find that a complex semantic analysing tool can be built up with various open-sourced software tools. This makes it possible to deliver pedagogical applications at a more acceptable speed and cost.