The book contains an introductory course on the Go language for system programming, describes the use of Go to implement competition and parallelism, talks about the interoperability between existing C code with new Go code, and also explores the possibilities of implementing Go to improve the performance of various distributions. The second edition contains a description of the Go language in version 1.2 and a description of the TinyGo implementation, in addition, new examples of using the language are given.