I started work on TeXcount in 2005 due to a simple need to perform word count on a manuscript. It has since been maintained and improved primarily as a service to the LaTeX community.
The first version I made available on my web page was close to the first working version: version 1.0, summer 2005. Up until version 1.4, this was still written primarily with my own use and way of writing LaTeX in mind. However, with version 1.4 in January 2006, I cleaned up the code quite a bit to make it more available to others.
A request to upload TeXcount to CTAN initiated a major upgrade: version 1.9 was uploaded in January 2008 as an early release on the way to getting version 2.0 ready, with version 2.0 arriving in February. This introduced the ability to leave instructions for TeXcount in the LaTeX code: e.g. macro handling rules. Since version 2.0, there has been a number of features added, but the core part remains with only few modifications.
TeXcount, the script as well as the accompanying files and documentation, is distributed under the LaTeX Project Public License which grants you, the user, the right to use, modify and distribute the script. However, if the script is modified, you must change its name or use other technical means to avoid confusion with the original script.