Just the other day I was complaining about writing out conventional dots-on-lines music using notation software. “It needs a regular, steady beat, and needs to know how many beats will be in each bar before it begins to fill them with notes and silences.” I haven’t used notation software for years because it didn’t seem to want to let me do anything fun.
I generally don’t write for human beings anyway, so if I’m writing out musical instructions to be understood by a machine I’d rather use sequencer programs which can give you more direct control over your data. This means I end up punching in lots of numbers by hand* or writing scripts to generate the numbers for me. Now someone’s found out by accidentally hitting the tuplet key twice in Sibelius that you can create all sorts of groovy irrational rhythms and temporal illusions by building up stacks of multiple tuplets, like so (illustrations and sound samples follow).
* or by banging my head against the computer keyboard Don Music stylee.