I am using Lisp more, and big changes to my consulting business
I haven't been using Lisp languages much in the last five or six years since I started using Ruby or Haskell more often to experiment with new ideas and projects. Now that I am winding down my remote consulting business (more detail later) I want to spend more time writing:
I have three book projects that I am currently working on: "Practical Scheme Programming (Using Chez Scheme and Chicken Scheme)", "Ruby Programming Playbook", and a fourth edition update to "Loving Common Lisp, or the Savvy Programmer's Secret Weapon". All three of these books will be released using a Creative Commons no commercial reuse, no modifications, share with attribution license, so copies of these eBooks can be shared with your friends.
I was very excited when the fantastic Chez Scheme system was open sourced but some of the excitement was soon tempered by the time required to get much of my existing Scheme code running under Chez Scheme and R6RS. To be honest, much of the work for this book is simply for my own use but I hope that I can help other Scheme developers by organizing my work to get set up for Chez Scheme development, by supplying a large number of useful code "recipes", and documenting techniques for using Chez Scheme. I used to mostly use the (also excellent) Gambit Scheme, created by Marc Feeley, for writing small utilities that I wanted to compile down to compact native code. Scheme works better than Common Lisp or Clojure for generating small and fast executables with fast startup times.
I have a long history using Common Lisp, starting when I upgraded my Xerox 1108 Lisp Machine in 1983. I have written two successful commercial products in Common Lisp, used a derivative of Common Lisp to program a Connection Machine, and used CL on several large projects.
To brush up on Common Lisp, I am (once again) working through several books written by people with far better Common Lisp programming skills than I have: Edi Weitz, Peter Norvig, and Paul Graham. My Common Lisp code sometimes suffers from using too small of a subset of Common Lisp and I don't always write idiomatic Common Lisp code. It is definitely time for me to brush up on my skills as I rewrite my old book.
I have only written one Ruby book (for Apress) in the past but since I use Ruby so much for small "getting stuff done" tasks, I have intended to finish a new book on Ruby that I started writing about two years ago.
I hope to have all three of these writing projects complete in the next 18 months. When I published my last book "Introduction to Cognitive Computing" last month, I counted my titles and realized that I have written 24 books in the last 29 years. I love every aspect of writing, and I have met many awesome people because I am an author, so the effort is very worthwhile.
re: large changes to my consulting business:
I have combined doing remote and onsite consulting for the last 18 years. I used to very much enjoy both remote and onsite work but in the last few years I have found that I don't enjoy working remotely as much as I used to while I have been very much enjoying my onsite gigs where I get to meet my customers and not just talk on the phone. Working onsite is a very different experience. So, I have stopped accepting remote work except for longer term projects with some onsite "face time" with customers.