The sofsdk.zip file you have requested: Official Releases / Others / SoF SDK - 3.56mb is not available. Perhaps try browsing all files for the game Soldier of Fortune and upload any files you want to share or are missing. This is the only information we could locate:
This version of the Software Development Kit has expired. There is a newer version available which can be downloaded here.This old version 1.0 is stil available for download for whatever reason you need it, but it's adviced to download the new, updated version. Again, click here to get that, it's version 1.1, 5.2 MB big and includes the source code for the game.