From: ClassCastException on
In dealing with Java, OpenJDK, and Clojure stuff in recent months I'd
come to suspect that open source licensing is itself a source of trouble.
Notably, Clojure's license is incompatible with the GPL, under which
large chunks of other open source software is licensed. It seemed to me
that a measure intended to free up software so anyone could develop it
and contribute to it, as long as their contributions in turn became
available to others, had somehow gotten itself tangled in knots that
actually hindered this purpose.

So I decided to do a little reading on copyright in general. Why does it
even exist? The nominal purpose, it turns out, is to "promote the
progress of science and the useful arts" by providing a way for the
creators of any popular or important work to ensure remuneration,
basically. Which smells suspiciously like a grant of monopoly -- which,
barring the notion of "fair use", it basically is. Furthermore there are
a LOT of blogs out there expressing serious criticism of copyright,
pointing out that fair use is not in most cases a workable defense even
when it should be, and that copyright has been twisted away from its
original purpose by corporations seeking to extend and tighten their
control over lucrative media and software properties.

It thus seems that copyright was twisted away from its original purpose,
to which it might have been poorly suited to begin with, and open source
licenses try to twist it back toward that purpose. Double twist. Is it
any wonder it's getting tangled in knots?

Here's something even weirder though: my blog-surfing led me eventually
to http://www.againstmonopoly.org/index.php?perm=593056000000003021 where
there is mention of open source licenses being not without problems. And
I saw something familiar out the corner of my eye: [insult deleted] in
the "most recent comments" thing at the right. Curious, I clicked on "My
Growing Library of Banned Books" and wouldn't you know it, it is indeed
Twisted, flaming some poor pro-copyright person who showed up at the blog
to criticise it. Talk about sticking your head in the lion's den,
especially when one of the lions is Twisted!

Upshot: I think I'll use BSD-type licenses for now. They're compatible
with almost anything, license-wise, including the GPL and Clojure's
license, and have a decent level of respect in the open source world. I
don't think I can go far wrong if I use the two-clause BSD license on my
code.

If anyone knows differently, or has any other insights on the licensing/
how-to-make-money/copyrights-are-they-good-or-evil issue as they apply to
Java/JVM developers, I wouldn't mind knowing what they have to say.
Please do try not to turn this into a useless anti-Twisted flamefest
though; this newsgroup has gone a good long time without one of those and
I for one like it just fine that way.