I often need to query an XML document without having to load it into a native XML database. In a perfect world, I would simply load the document into my editor, sprinkle some XQuery into the document, highlight the portions I want to evaluate, then hit a key combination to view a new window with the results. The whole operation should take all of a few seconds for a large class of XML documents and queries.

Thankfully, this is indeed a perfect world. And, I'm an Emacs user.

I just found a beautiful interpretation of Mozart's Requiem. Click the play below to hear it.

ISBN 978-1-60489-063-1 (Trade Paper) 978-1-60489-062-4 (Library binding) Katie Wainwright just published a new book! It will be available this fall, in the usual places (Amazon, Barnes And Noble, and so on). Congratulations Aunt Katie! Links: Library Thing

Here's how you can use ffmpeg to convert a video (an MP4 video, for example) to an MP3 that you can load on your MP3 player:

    ffmpeg -i video.mp4 -f mp3 -ab 192000 -vn music.mp3

But there's a catch: You have to have ffmpeg and the libavcode-unstripped-52 packages installed on your computer. The problem is that second package is available in the multiverse respository only. To enable the multiverse repository, select Administration from the System menu, then Software Sources.

IBM DeveloperWorks just published an article of mine: http://www.ibm.com/developerworks/xml/library/x-optxmldb/index.html

I just found an article titled Querying s-expressions in Common Lisp that Slava Akhmechet posted to defmacro.org last year. (Yes, I know--old news. I have a lot of catching up to do.)

The article got me excited because I am an XQuery programmer and I've always wanted to see something like XPath in Lisp and in Perl. (Thanks Slava!) I've even mentioned this to my peers. But I'm not talking about a library to manipulate, navigate, or query XML.

A few days ago, I wrote a simple Quicksort implementation in Common Lisp. After that, I started to wonder how other lisps and Perl compared for sorting numbers.

I just read an article comparing the performance of Clojure, Java, Ruby, and Scala. As I read the article, I wondered how Common Lisp compares to the languages covered in the article.

I've written a simple multithreaded TCP server that uses sockets and a thread pool to handle client requests. This server is packaged into a class (DcServer) that can be trivial to use.

I was benchmarking PCs to try to determine where to put some Chattermancy code and I started to wonder once more where we are in the unintentional technological race to build a cheap computer that can outperform the human brain. I've done this exercise a half-dozen times over the years. Here's what I found this time.

Calculating how long it's going to take for PCs to become as powerful as the human brain is easy if you can make a few assumptions.