The sofsdk.zip file you have requested: Tools and Utilities / SDK / Soldier of Fortune 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:
The Soldier of Fortune SDK. It contains a version of Radiant for SoF, the BSP utilities, scripting compiler, GHOUL exporter, documentation, and the original map and script files for the first level of the game.