I have funding for software development to provide a UMAT interface in the parallel versions of the code from Smith I.M. and Griffiths D.V. "Programming the Finite Element Method", 4th Edition, Wiley, 2004.
I would be interested to hear about any open source UMATs available for download. I'd also like to hear from anyone who might like to use their closed source UMATs in a parallel environment.
The funding has been awarded by the UK National HPC Service HECToR to encourage the greater use of HECToR for Structural Engineering.