RoR and Ruby Licensing...

IANAL, but I used to redistribute Free Software...

In general, the answer is that (a) you own what you wrote
and (b) using Ruby or Rails libraries doesn't "infect" your
code in any manner. Static linking and inclusion of source
code are exceptions, but neither tends to be a problem. Use
of an interpreter or the supporting libraries is well-trodden
ground and isn't a problem.

Open Source licences aren't supposed to restrict the way in
which the code is used, only its redistribution, relicensing,
etc. So, as long as your use is within (say) a company, you
aren't likely to have any problem at all. Even when you are
redistributing software externally, the rules aren't onerous:

  * Don't claim that you wrote or own others' material.

  * Don't distribute binaries that are based on GPLed code
     without being willing to distribute the source code, as
     well. This could, for example, apply to distributing
     the Ruby interpreter.

     However, the "Library" (aka Lesser) GPL was specifically
     designed to handle this situation. In the unlikely event
     that the regular GPL was used AND the author is unwilling
     to accept the Lesser GPL AND redistribution is an issue,
     you might have a problem. But it's unlikely...

In any case, accommodating and courteous behavior will get you
out of most disputes. Conversely, strict adherence to legalisms
may be insufficient to avoid calumny, if you aren't perceived as
being courteous and acting in good faith.

-r

In general, the answer is yes. Due diligence requires you to
find out, however, about the precise terms of each license on
any software you redistribute. Ruby, for example, gives you a
choice of licenses.

As far as the GPL is concerned, I thrashed out this question a
number of years ago with RMS. As long as you don't declare a
"collection copyright" (but limit yourself to the copyright on
your own works) and don't try to override the terms set by the
original authors of the included software, you should be OK.

FYI, a visit to the www.opensource.org is always a good starting
point in these matters, as is a visit to www.fsf.org. You should
also read some of Richard Stallman's essays, in order to get the
rationale behind the GPL, etc.

-r