The GPL self-destruct mechanism that is killing Linux
Festering hacks, endlessly copied and pasted - thanks Eric!
Free software: A virus in Microsoft's eyes
This ability to freely copy lines from source code without giving anything in return is something the GNU directly stamped out with its licence, the GPL, which mandates that anything using GPL components should itself fall under the terms of the GPL. If you write a program and include in it work cut'n'pasted from GPL-licensed source code, your program also falls under the GPL and you'll have to make its source code available. This establishes a level playing field and enables Stallman's ultimate goal: the ability to freely modify whatever software is running on his computer and share it.
That's why Microsoft CEO Steve Ballmer declared the licence "viral".
When Unix was young, it was an elegant command-line driven OS, built around the idea that everything is a file and small single-function programs could be linked together with pipes to achieve sophisticated results.
But today's Unix descendants are large, complex graphical beasts, and so are their apps. Any significant modern application is a big project, which means teams of cooperating developers - and programmers are just people. Sometimes they fall out, sometimes they just want to go and do their own thing. Result: lots of competing projects.
Linux itself hasn't split is the forceful, charismatic leadership of Linus Torvalds, but - unfortunately - Linus doesn't scale. Very few projects get to have a Torvalds-like leader.
The other issue is that as the tools to build software mature and grow more powerful and flexible, it's getting easier for relatively inexperienced, unskilled programmers to assemble complex apps out of many supplementary components - subsidiary parts that they may not know very well. This increases the chances of people reinventing wheels which might differ in nothing more significant than their colour.
The GPL per se does nothing to prevent this, which is why forks are quite common. Sometimes it's because different developers want to focus on different things - which is why the original Linux clone of WinAmp, XMMS, has begotten the Beep Media Player, Audacious, Youki and two projects called XMMS2. Sometimes, rival projects happen over political differences - as in the resistance to KDE's use of Qt and C++ which led to the creation of GNOME. Today, they're joined by half a dozen rivals - along with umpteen Free Software web browsers.
It's widely held that the reason Linux itself hasn't split is the forceful, charismatic leadership of Linus Torvalds, but - unfortunately - Linus doesn't scale. Very few projects get to have a Torvalds-like leader.
So aside from careful choice of licence and project leadership, is there anything to be done? Perhaps not, but this might not always be a weakness. Diversity means adaptive radiation: some projects will win users, favour and support and thus prosper; less popular ones will atrophy. Occasionally, projects merge, as did Compiz and its forks Beryl, NOMAD and Compiz++.
Flock of C-gulls
This may turn out to be a defining aspect of free and open-source software (FOSS). From the start, part of the Unix philosophy was that it was a mosaic of many smaller parts. Linux has been memorably described as less an operating system, more a flock of several thousand separate packages flying in close formation. Perhaps its vast numbers of alternative, competing components is actually a strength.
The other possibility is that if the industry moves beyond C and toward other languages, that pooled resources akin to Perl's CPAN or Python's PyPI will become more widespread, making code reuse easier and more convenient. Another trend that might help is languages that run on top of shared runtimes, such as the JVM or Microsoft's CLR, allowing code in one language to call libraries written in different ones.
If that becomes an insuperable problem, well, there are others FOSS operating systems and platforms out there - plus some with very different approaches to OS design waiting to be discovered.
Linux is a remarkable wad of code, but as operating system design expert Professor Andrew Tannenbaum pointed out in 1992, it was already obsolete. The answer may lie in not merely reinventing the wheel, but the entire car - or replacing it with a bicycle instead. ®