ASCIIFlow - an interactive web site to produce ASCII drawings
The Request for Comments (RFC) contains all the specifications of the Internet protocols. Since the publication of RFC1 on 7 April 1969, these documents have been published in ASCII format. Compared to word processing tools, ASCII has the main advantage that old documents remain easily readable on any platform fifty years later. Unfortunately, it also means that RFC authors need to sometimes struggle to use ASCII art to prepare figures such as state machines, protocol messages, …
Over the years, the Internet Engineering Task Force has developed tools to help authors to format their RFCs. Troff has been popular for some time, but today xml2rfc is often used together with kramdown. With these tools, the authors can use the simple markdown syntax and obtain their Internet draft in the required formats.
For the ASCII figures, it often remains an art although some authors will happily start from figures found in older RFCs and adapt them to their needs. The ASCIFlow provides a nice graphical interface that allows to easily produce ASCII art for RFCs and Internet drafts.