I did this as kind of a hack, I thought it would be a goof to have my software running in an art exhibit. Since then I've come to have a lot of respect for actual artists, who have actual artistic goals they are pursuing. I'm not sure if I did.
A hack that I made with a neighbor, to put our local police blotter in a more convenient framework (he was suffering from problems with car breakins, but that's not a very good reason; this was mostly for the sheer pleasure of hacking).
Vaguely is a tool/hack for exploratory data visualization, based on Vega-Lite, "a high-level grammar of interactive graphics". Vaguely is a partial translation of that grammar into a Scratch-like blocks interface, making it easier to experiment with different visualizations.
This hack was a system I built while working in the SRI Bioinformatics Group. A working example of a "knowledge spreadsheet", which just means a spreadsheet-like interface that can do semantic or relational computations.
This page wants to be called both "hacks" (descriptive) and "hack" (to use as a
link/tab from natural text). Roam doesn't let you do that easily, one of its most annoying misfeatures.
I'm also starting to get annoyed at myself for introducing this term as a formal tag. A good hack does not need to call itself one, and I feel like I'm shoehorning all sorts of projects under that label for my own convenience, and doing some damage to its semantics in the process.
However, these all do have something in common, which is that I did them mainly on my own initiative, whether or not they were part of a paying job. That makes them seem like hacks in a nontechnical dimension, simultaneously creating something and getting away with something.