XFOIL is an interactive program for the design and analysis of subsonic isolated airfoils.
It consists of a collection of menu-driven routines which perform various useful functions such as:

* Viscous (or inviscid) analysis of an existing airfoil, allowing
o forced or free transition
o transitional separation bubbles
o limited trailing edge separation
o lift and drag predictions just beyond CLmax
o Karman-Tsien compressibility correction
o fixed or varying Reynolds and/or Mach numbers
* Airfoil design and redesign by interactive modification of surface speed distributions, in two methods:
o Full-Inverse method, based on a complex-mapping formulation
o Mixed-Inverse method, an extension of XFOIL's basic panel method
* Airfoil redesign by interactive modification of geometric parameters such as
o max thickness and camber, highpoint position
o LE radius, TE thickness
o camber line via geometry specification
o camber line via loading change specification
o flap deflection
o explicit contour geometry (via screen cursor)
* Blending of airfoils
* Writing and reading of airfoil coordinates and polar save files
* Plotting of geometry, pressure distributions, and multiple polars