Since the beginning of the century, Wien2K has proven to be a very powerful player in computational condensed matter and materials physics.

Wien2K is an all-electron periodic DFT code based on the Augmented Planewave + Local Orbital [APW+lo] method, and also widely known as Full-Potential - Linearized Augmented Planewave [FP-LAPW+lo] method, or simply LAPW. It is known or said to be one of the most accurate methods for modeling solids. Wien2K is very nice, but it is not free.

Do you know of any open-source & community LAPW codes alternative to Wien2K?

What has been your experience with them?

I am particularly interested in codes that invite developers.