I have just uploaded V3.1.14 to www.sheetcam.com. This version has the following changes:
Added: String library to Lua macros
Added: Plugin API and SDK
Fixed: Installer not starting SheetCam
Plugin developers, look in the SDK directory in the SheetCam installation directory. You will find demo projects for both Visual Studio 2005 and Borland C++ Builder 6. In both cases when you compile the dll it will be placed in the SheetCam directory ready to be tested. Note for Visual Studio you must run MakeLib.bat from the command prompt (don't just double click on it). You will have to do this every time the SheetCam API changes.