Linux/GNU History

•  Unix was invented.
• It was written in assembly (not portable)
• When changing the target, the assembly instruction set is different, so porting of Unix was a long story
• Inventors of Unix invented C, and wrote the Unix in C (Portable)
• Now, all you need when changing the target, is to make its compiler, which map C instructions into assembly instruction

• GNU
  
  
  
  
• Richard Stallman, an activist who called for free SW, decided to make a Unix like OS, but open source.
  It is GNU (GNU Not Unix)
• GNU project started with gcc (GNU C Compiler), gdb (GNU debugger), and other utilities.
• GNU project made the GPL (GNU public license), which implies that any one that will use a GPL licensed SW shall make his product open source

• Linux

• Linus invented an open source kernel.
• GNU decided no to build another kernel, just integrating Linus kernel with GNU tool chain (gcc, gdb, ..etc) and GNU apps and utilities (GIMP, gzip, ...etc), Linux OS is launched

•  There are 2 GUIs for Linux:
• KDE: better, but not open source
• GNOME:
  Open Source.