Complex sentence: Linux-libre is a project that releases and maintains modified versions of the Linux kernel which has taken away every piece of software that does not includes source code, or its source code is obfuscated or released under proprietary licenses.
Split into simpler sentences: Linux-libre is a project that releases and maintains modified versions of the Linux kernel. Their kernel version removes any software that does not include source code, has its source code is obfuscated or released under proprietary licenses.