摘要：In the past decade, we have witnessed spurt of activ- ity in the area of distributed computing. Several new dis- tributed computing paradigms have emerged that promise to facilitate the delivery of software-based services at un- precedented scale. This includes the emergence of Grid, Cloud, Sky and Fog computing technologies. These middleware technologies are increasingly used for the development of data and computationally intensive, Web-based applications, involving the use of geographi- cally dispersed resources and potentially huge number of users. With our current experience, it may be forseen that in the future applications will be completely detached from the underlying infrastructures and will be able to elastically scale based on dynamically changing require- ments. Middleware solutions facilitating such applications are currently of interest to many knowledge based indus- tries and businesses, active in the areas of engineering, fi- nance, medicine, biology, pharmacy, telecommunications and so on, since they are facing challenging scientific and engineering problems.
