If you want to develop external functions for Compact JADE, you require the following software.
Microsoft VS2005 or VS2008.
To build support DLLs for Windows Mobile 6, download Windows Mobile 6 Professional or Classic Software Development Kit refresh (version 6, published 5/1/2007) from http://www.microsoft.com/en-nz/download/details.aspx?id=6135.
To build support DLLs for Windows Mobile 5.0, download Windows Mobile 5.0 Pocket PC SDK.msi (version 5.0.14343, published October 5, 2005) from http://www.microsoft.com/en-nz/download/details.aspx?id=42.