We offer Single user executable-only licenses

  • US$2500. Single user conducting research at or for a for-profit organization
    • includes 2 years of free upgrades and support
  • Free. Single user conducting education or research in medical physics or radiation biology at and for a non-profit organization
    • includes 1 year of free upgrades and support
    • can be renewed each year as long as our support funding remains in place from the National Cancer Institute

While most users will find that they can do everything they need with TOPAS without writing any C++, our standard licenses include the ability to extend TOPAS by writing and plugging in your own additional geometry components, scorers, filters and physics lists. We will also provide an exchange where users can share their TOPAS extensions with others.

Supported Operating Systems:
  • OS X 10.11 or newer
  • Debian8
  • Debian6
  • RHEL6

For answers to some common questions, see our FAQ

To read our exact license terms and apply to become a TOPAS user, go to Registration