The 5th edition of Learning the vi Editor contains many improvements. We have expanded the treatment of existing topics, and we have added some completely new topics and features:
The book has a quick-reference guide to all commands. This guide, located at the back of the book, can be pulled out and used as a handy reference card.
ex editor commands are discussed more fully. In Chapters 5, 6, and 7, the complex features of ex and vi have been clarified by adding more examples, in topics such as regular expression syntax, global replacement, .exrc files, word abbreviations, keyboard maps, and editing scripts. A few of the examples are drawn from articles in UNIX World magazine. Walter Zintz wrote a two-part tutorial on vi that taught us a few things we didn't know, and that also had a lot of clever examples illustrating features we did already cover in the book. Ray Swartz had a helpful tip in one of his columns. We are grateful for the ideas in these articles. The increased emphasis on ex warranted a summary of all ex commands, so we added an alphabetical listing in Appendix C, ex commands .
 "vi Tips for Power Users," UNIX World, April 1990; and "Using vi to Automate Complex Edits," UNIX World, May 1990. Both articles by Walter Zintz.
 "Answers to UNIX," UNIX World, August 1990.
Minor additions or corrections have been made to the discussions of basic vi commands. Many of these additions are based on comments by Kismet McDonough of O'Reilly & Associates, Inc., and by Steve Simmons, who teaches vi on the West Coast. The comments were very useful.
The following people at O'Reilly & Associates, Inc. worked on the 5th edition: Daniel Gilly wrote most of the new material; Mike Sierra produced the manuscript; and Chris Reilley designed the quick-reference guide and redesigned the original figures.