2.1 Free software

One direct consequence of ``open source'' is ``free software''. Once the source code of a program is available, and that the tools to produce a program from source code is also free, it essentially means that the program itself is free of charge.

It is also possible to acquire the source code of an open source program, modify it, and then produce the program. This means it is entirely possible to customize open source programs for specific needs, all for free.