In the days of Electron bloatware, it's refreshing to see a program that is so light in terms of size. Unfortunately, at least on a 4K screen, the interface is a bit laggy and it uses a lot of CPU.
A web app would have been cross platform (including just web), had a superior UI (in both speed and UX) — and with a less bloated Electron alternative like Tauri — better in just about every way that matters.
It has a freepascal/lazarus project file, so it can be compiled for a lot of platforms, i don't about midi drivers on those platforms, so midi could not work or need more code.
Their website makes their definition of portable very clear in "What makes a portable app special?".
It's quite clear they mean more a (much) stricter variation of the "no installation" definition than the "easily buildable on other OS" definition. Though they do mention execution under translation environments as a requirement.
There were companies that specialized in 'porting' games to Mac using/packaging Wine long ago. It was certainly effective in the Intel Mac days and newer CPUs can certainly run software that predates that well. Heck browsers can run OSes and games in JS/Wasm.
https://www.blaizenterprises.com/cynthia.html#help--what-mak...
It's quite clear they mean more a (much) stricter variation of the "no installation" definition than the "easily buildable on other OS" definition. Though they do mention execution under translation environments as a requirement.
This is (pun intended) music to my ears!
Then I saw the instrument / note grid, and the keyboard UI - this looks fun!