One of the most fundamental challenges when looking for changes in the progression of something is to search two files for differences. This can be accomplished using tools in a programming shell, but this page contains links to some of the many diff checkers on the web.
Likewise, while RegEx are a powerful tool for processing text, they can be a challenge to work with. The tool I have added here is one I have used often to hone my work on regular expressions.
This page may also include a few other bits and bobs useful to folks performing taks like coding and web development.