How do we develop an open source software based on existing version?

Question

I keep reading that the source code is available for all to manipulate and use it and change it but where can i find these source codes of oss?
where can i find source code of unix?

Answer 1

All versions of Linux have the source freely available.



UNIX itself was proprietary software, not open source. There are open source recreations or look-alikes such as BSD and Open Solaris.



CentOS (RedHat source, also used for WhiteBox, Scientific Linux etc.)

https://wiki.centos.org/Sources



FreeBSD:

https://www.freebsd.org/developers/cvs.html



OpenSolaris

https://distrowatch.com/table.php?distribution=opensolaris



You probably need to use a tool such as GIT or Subversion to retrieve the source masters from the repositories.

Answer 2

Any Open source project will have their source code available to download.



Unix isn't Open source, that would Linux.



Now something like Linux is an incredibly complex project. You wouldn't try and write your own version from scratch. You would work on one sub-project or application, often in co-operation with other coders, beta testers etc.

Answer 3

You basically take the code and start tweaking until it suits your needs, bringing in bits of other projects and integrating them or removing features you don't need. As far as Unix source code in concerned your best bet is the FreeBSD source, which for legal reasons has to be called Unix-like even though it was derived directly from AT&T Unix and influenced System V. You can also find the sources to Darwin, Apple's operating system core that fuses BSD and Mach, and build from there since Darwin is UNIX certified. If you search "FreeBSD source code" and "Darwin source code" you'll find the repositories.