A finite element program based on an explicit time stepping algorithm
Simulations are made on a virtual three dimensional model which can be created with a pre-processor or with the built-in Fembic language. Results are viewed in a post-processor.
Impact is designed to interface with the included pre- and postprocessor by default, but there are also interfaces available for more advanced pre-and postprocessors such as GiD or Gmsh. Impact also has rudamentary support for Nastran file format.
Development is made by a team of volunteers from all over the world with the aim of creating a clean and compact program which is simple to understand and use.
Impact is licensed under the Gnu Public License which makes it free to use and modify as long as you release and publish your improvements under the same license.
Impact is written in Java which means it can be run on most hardware and operating systems.