Recent Grid projects, such as the Globus Project, provide a set of useful services such as authentication and remote access to resources, and information services to discover and query such remote resources. Unfortunately, these services may not be compatible with the commodity technologies used for application development by the software engineers and scientists. Instead, users may prefer accessing the Grid from a higher level of abstraction than what such toolkits provide. To bridge this gap, Commodity Grid (CoG) Kits provide the middleware for accessing the functionality of the Grid from a variety of commodity technologies, frameworks, and languages. It is important to recognize that these Commodity Grid Kits not only provide an interface to existing Grid technologies, but also bring Grid programming to a new level by leveraging the methodologies of the chosen commodity technology, thus helping the development of the next generation of Grid services. Based on these Commodity Grid Toolkits, a variety of higher level Grid services are far easier to design, maintain, and deploy. Several projects have successfully demonstrated the use of Commodity Grid Kits for the design of advanced Grid Services and Grid Computing Environments.