http://liblfds.org/

There is no license. You are free to use this library in any way. Go forth and create wealth!
If however for legal reasons a licence is required, the license of your choice will be granted, and license is hereby granted up front for a range of popular licenses : the MIT license, the BSD license, the Apache license, the GPL and LPGL (all versions thereof) and the Creative Commons licenses (all of them). Additionally, everything is also placed in the public domain.