This domain XAV.COM is going to be sold.

Home > Fluid Dynamics Search Engine > Free Key

For many years, the Fluid Dynamics Search Engine (FDSE) was $40 shareware. Supporters would receive a registration key that they could paste into their script. Those who paid were allowed to remove the publicly-visible copyright notice and link back to

As of October 2015, FDSE is now free. Everyone is welcome to remove the publicly-viewable copyright notice and link back to Nobody needs to buy or enter a registration key, but if you'd like to do so, a free universal key is:

I am very grateful for the years of generous support from so many users around the world.