While at work I ran across a project that required a Python application to be run on a recurring cron job and I wanted a way to make sure that if for whatever reason the Python application ran longer that the period of time before the next cronjob was set to run that it would in fact not run, but rather skip that run until the first Python app’s execution completed. After discovering that on Linux the flock tool existed expressly for this purpose I decided to give it a try and noticed some shortcomings and other issues which lead me to the creation of Highlander. For a list of reasons why I chose to create Highlander see the F.A.Q. in the README and along with that it was fun to create a fully tested and deployed python library to PyPi. I posted this code to Hacker News from which it received 227 (and counting) stars on Github, so somebody else besides me must find it useful.