This paper describes the design and implementation of the core language in the software generating system NDHD as well as its application status. This system is based on the ideas of system programming language and bootstrapping technique. The essence of the system is the selfcompiler AC0 of the core language L0 （in 655 machine language）. By applying bootstrapping technique

the selfcompilers of the succeeding languages L1

L2

…? Ln may be automatically generated in turn. At present selfcompilers of the first and second generations have been successfully generated by this system. The results indicate that not only production rate has been increased by four times

but also compiler capabilities can be easily extended. The data structure

control structure

program structure

input-output components in L0 as well as the compiling algorithms used in AC0 have been briefly described