Python
cgikit.wintab - As part of the Python Computer Graphics kit, the wintab module allows you to use Pyhon to get pen data via the WinTab interface.
.NET
WinTabControl - A demo app showing using the WinTabDN nuget package with a Windows application to show current poition pressure, tilt, etc. Uses .NET Framework 4.7.2
https://github.com/Apostolique/Apos.WintabDN - Uses .NET Standard 2.0
Windows
https://github.com/perlfu/WintabEmulator - drop-in replacement for WINTAB.DLL that emulates the WinTab API but uses Windows Ink under-the-covers
Rust
https://github.com/thehappycheese/wintab_lite - use WinTab API from Rust
Utilities
https://github.com/jchv/wintab-interposer - logs all WINTAB API calls
Sandbox apps
https://github.com/TheSevenPens/WinTabPainter - a primitive "paint" app to prototype and explore ideas for drawing tablets.