I wrote some VBA software for personal use a couple years ago and gave it the really geeky name "BLASDOF". It uses a nonlinear SDOF dynamic analysis routine based on the publicly available UFC blast documents and ASCE's Design of Blast-Resistant Buildings in Petrochemical Facilities guide. My programming skills are pretty basic but I found the learning process was much more valuable in the end than the actual final product. If anyone wanted to try writing their own blast software, I'd be happy to help out with V&V, bouncing ideas off or whatever else.