Excel and then VBA macros for Excel, or the equivalent in LibreOffice. Use it to do some useful things. Make a budget, calculate the three basic financial statements, simulate some basic processes like exponential growth and predator/prey. Then VBA to do some basic iterating over strings and other similar things. Write a little text mode adventure game. You could even use Word for that and have it print the transcript as you go along.
Then the basics of networking. Set up a little LAN, difference between router and switch, get Bonjour/ZeroConf working across some number of hops.
I'd also agree with Excel... it works on many levels and allows incremental progression.
Some ideas: Many audiences. Some might want to get exposure to programming, some might have developer as a career option, and some might want neither but would still find a lot very useful.
Excel as a numbers tool: Recording data, simple automation (cells with formulas), concepts like normalisation. Extending this as a financial tool, or analysis tool.
Applications, that might fit those going to college or those going into the workplace: Routine tasks that need data recorded or analysis. Book keeping/double entry accounting. Applications in other subjects (biology, physics, economics, even English e.g. parsing text).
Excel/data as a communication tool: Analysis of data, visualisation (introduce some Tufte perhaps), objectivity, include in other applications.
Excel/VBA as a stepping-stone to programming. A nice feature of Excel is that it excels in allowing the same problem to be solved in multiple ways. So perhaps a stream of the class for programming concepts (VBA, later Python/R?) while another stream takes applied assignments (individual/group) using Excel's in-built functions?
Version control, however primitive.
Ethics, information security, data protection laws, tax laws in all the above?
I wholeheartedly recommend that people get some basic grasp of Excel, because they will pretty invariably run into it in a white-collar job, and some blue collar ones.
Excel and then VBA macros for Excel, or the equivalent in LibreOffice. Use it to do some useful things. Make a budget, calculate the three basic financial statements, simulate some basic processes like exponential growth and predator/prey. Then VBA to do some basic iterating over strings and other similar things. Write a little text mode adventure game. You could even use Word for that and have it print the transcript as you go along.
Then the basics of networking. Set up a little LAN, difference between router and switch, get Bonjour/ZeroConf working across some number of hops.