Online Examination is an essential ingredient in electronic and interactive learning, however, in educational environment most of examinations are done in the classical paper-based way. Adopting and developing an online examination system acts as an active research area in recent years. This Book reviews the state-of-the-art and the-art-of-the-practice for nine general-purpose online examination systems found in the literatures, as well as, some dedicated industrial systems based on seven elected intertwined features; namely: Secure login, resumption capability, multi-instructor, random question selection, random questions distribution, random choice distribution and portability implementation method. In spite of the implementation of these systems is promising, these systems have some bleeding points. For instance, by practicing the existing examinations system, some challenging features are found (acts as merits) and others are missing (acts as demerits). Among these features; namely: the resumption capability and the combination of randomization features are missing in all reviewed systems. Fix and build from earlier works, this book proposes an Online Examination System (OLES).