Windows
Self-contained ready-to-run EXE file
Note that when running this for the first time, Windows is likely to warn that it does not recognise the "app". To run the program you will need to click "More info", then "Run anyway".
MacOS
Self-contained executable file
In theory the instructions below should work, but I don't have a Mac myself to test and one person who tried this had problems. So if you can get this to run I would appreciate if you can let me know.
In the Mac Finder, right-click the downloaded file and select "Open" from the menu. You will get a warning that the program's developer is unidentified, to run the program you will need to click "Run anyway".
Linux
Self-contained executable file
After downloading this file, open a terminal window in the same folder as the file. For the first time only, we need to change the file's permission mode to make it executable by all, so type:
chmod a+x tartaniser-linux64
Then to run the program, type:
./tartaniser-linux64
Source Code
This can be run with any installation of Tcl/Tk, see https://www.tcl-lang.org/
Online Version
This is a version of the program which can be used online without downloading any software. You can save a design by downloading the .tartan file to your PC, and load a design by uploading from your PC. The saved designs are compatible with the desktop version of the program.