From Goldcup Software and Design:
If you're interested in Celtic designs then download KnotWorker and start creating your own now. No experience required.
KnotWorker is the quick and easy solution to making Celtic knotwork patterns, whether professional or just for fun, in print or for the web.
KnotWorker is Goldcup Software's free knotwork design tool for Windows. Even if you have no experience of Celtic knotwork design you'll be creating knots in minutes.
Here are just a few features:
Quickly draw knotwork designs without any previous experience.
Edit the flow of knots using the Breakline Editor.
Arrange your designs on a page using drag and drop.
Use the 60 KnotStyles supplied with KnotWorker to give character to your knots - or create your own.
Add image effects, including colour phase and outline.
Quickly change the colour of a knot, rotate, flip, and control layer position.
Save your design in the Windows Bitmap format for use in your favourite word processor, DTP program or graphics editor.
Save your design in the native KWD format for editing later.
Tutorials teach you how to draw knots and how to create your own KnotStyles using the KnotStyle Editor.
What's new in this version:
Version 1.2.1: Now free to download and use.