I've been reading about software licenses for a few hours because of the reason that I want to release a software commercially. I'm no lawyer and I'm incredibly bad at understanding licenses.

Perhaps my question is very trivial but anyways pardon me for my ignorance. So the question is if I include any standard C library header (ex. math.h) am I supposed to release it (my program) under GPL? As the notice at the top says so, or is that notice targeted for people MODIFYING it and not USING it? O and BTW, I'm using MinGW/GCC and I've read that you are not obliged to release it under GPL as long as only the compiler is used, well then how about the Standard C Headers that have seperate copyright notices in them?

PS: If I am obliged to release it under GPL, how can I make a program to be released commercially without relying on that library/header that I need (that is in the standard C headers)?


The C library & headers included with most unix-type systems is NOT licensed under the GPL. It's licensed under the LGPL (L for Lesser or Library, depending).

With the LGPL, you can use the library in your code WITHOUT releasing your code under GPL.

So you're ok on that library. Be sure to check all the libraries you use, however, there are a few out there that are GPL.

  • I see, thanks for the anwer. One last question though are the other libraries that are included in MinGW under LGPL also? I mean the likes of cstdio, cstring. – John Mark Feb 8 '14 at 4:57
  • please disregard the previous comment, again thanks for the answer. – John Mark Feb 8 '14 at 5:10
  • However, make sure to link dynamically, not statically. – Johannes S. Feb 8 '14 at 13:19

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