What does open source mean?

I hear “open source” a lot on programming languages and stuff. But I don’t know what it means. Please tell me.


There are lots of definitions, but it really comes down to this: the source code of a program are the words that some programmer typed to make the program.

For example:

   print("hello world.")

Open Source means that the source code for the program is available for the public to use and re-use in some way. Anyone can download the source code, modify it, and create their own version fo an open-source program.

For example, Linux is open source. Anyone can use the Linux source code to create their own version of Linux, and several companies do just that.

Windows is NOT open source. Only Microsoft has the source code for Windows, and only Microsoft gets to create new versions of Windows and modify Windows.

There’s a lot more to it than that, but that’s the gist of it. Open source = you can download the source and compile it yourself. Closed source means you can’t.

Look at Valve Engine used in some popular games such as half-life 2 and portal, this is completely open source and allows users to create their own versions of the game, even as commercial products as long as Valve gets a cut (nothing’s free!) an example of this is Garry’s mod, JBs mod, counter strike and others. Open-source just means that the code that makes up all the program and usually assets aswell such as models of weapons and players. Hope that cleared it up for you!

Edit: The Valve engine is C++ based and allows for lua to executed alongside it.

Ok thanks