The document summarizes four major extension systems in India:
1) The first line extension system established by ICAR in 1971.
2) Extension systems run by the Ministry of Agriculture and state departments.
3) Systems run by the Ministry of Rural Development and state departments.
4) Development work by voluntary organizations.
It then provides details on four major transfer of technology projects under the first line extension system: the All India Coordinated Project on National Demonstrations, Operational Research Project, Krishi Vigyan Kendra program, and Lab to Land Project. Krishi Vigyan Kendras were established in 1974 as grassroots institutions for training farmers and disseminating agricultural technologies.