Hitchhiker's Guide to the Internet is a German introduction to the technical aspects of the Internet. This book explains both the low-level protocols IP, ICMP, TCP, and UDP and the high-level protocols SMTP, POP3, IMAP4, NNTP, HTTP, Gopher, FTP, IRC, DICT, Finger, Daytime, DNS, and Whois.
adoC is a source code documenting system written in awk and shell script. It produces documentation in LaTeX format which resembles the Unix man pages. The documentation is generated from comment sections in the source code, which are marked by two special character sequences and internally divided into sub-parts by keywords. The system can be used with almost any kind of programming language.