XFOIL is described as 'interactive program for the design and analysis of subsonic isolated airfoils. Given the coordinates specifying the shape of a 2D airfoil, Reynolds and Mach numbers, XFOIL can calculate the pressure distribution on the airfoil and hence lift and drag characteristics'. There are four alternatives to XFOIL for Windows and Linux. The best alternative is javafoil, which is both free and Open Source. Other great apps like XFOIL are xflr5 (Free, Open Source), QBlade (Free, Open Source) and Profili 2 (Paid).
QBlade is an open source wind turbine calculation software, which integrates XFOIL/XFLR5 functionality, and allows the user to rapidly design custom airfoils and compute their performance polars and integrate into rotor design and simulation.
Profili is a software developed to help the 'do it yourself' modelers. This new version can assist you in: Searching for the right airfoil for your application Creating new airfoils Analyzing the airfoil aerodynamic and more.