We have now added the spreadsheet and dll files to the downloads page so it is (at last!) more than just an image. You will need to generate a licence to unlock the stochastic spreadsheet functionality, so please download and run the system code generator and email the syscode.txt to me to receive your licence. For now the unlicensed version just allows deterministic calculations and breakthrough curves, whilst the licence unlocks the stochastic capability. Licences are perpetual and the first few are free whilst I explore how I manage licences.