Thanks for the incentive, but it's not needed and if I do get around to it, it'll of course be open source.

The main difficulty I had with writing a command line utility is figuring out the UI in a console. Suggestions are welcome of course.

Also, there are two possibilities for a client: the first queries an API on explainshell.com by sending it a command line. This has the advantage of the client being thin, and using the centralized man page database which is probably more accurate. But this means that you're potentially not explaining the exact command you're running locally, which may be confusing.

The second option is to run the man page parser, matcher, etc. locally against the man page on your machine.