The official developer offers a free demonstration version.
With PolyBoard, you can:
The 6.05 update focused heavily on refining "Project Mode" and expanding language support. Key improvements included: polyboard 6.05 free download
File sizes that are too small (e.g., 12 MB for a full CAD program) or password-protected ZIP files that require downloading a "password viewer" tool. The official developer offers a free demonstration version