SXFM is for Simple XML Feature Model format.
The major advantage of this format is that one can create feature models using a simple text editor. As a consequence, SXFM models can be typed in pretty quickly. For instance, we created an SXFM file for a feature model containing 287 features in about 10-15 minutes without a single mouse click.
The SXFM format also refrains from using tags for describing features thus keeping the size of typed XML files small.
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