I hope that you do not mind this long post, and are willing to read through it completely.
And possibly give me some good advice, and point me in the right direction.

I am a i5/System i ILERPG developer.
A craft that is getting less and less in demand here in The Netherlands. (One year without a contract already.)
This graph (only US based I believe) plots the situation more or less accurately : http://www.indeed.com/jobtrends?q=ruby%2C+rails%2C+rpg&l=&relative=1

So I need and want to learn new “tricks”.
I got interested in Ruby and On Rails somewhere in 2007 through this article : http://www.ibm.com/developerworks/data/library/techarticle/dm-0705chun/ and this website : http://midrange-ruby.org/.
But the impossibility/inability of companies offering IBM midrange timesharing, to provide a working Ruby (On Rails) environment on i5/OS PASE, and support it also, made it unsuitable for selfstudy.
You can sdd to that the additional premium of timesharing on i5 instead of older System i hardware.

I’ve just started to add the Mac OS X platform to my skill sets. Starting with OO.
After feeling comfortable with OO, the next planned step is MacRuby. (After reading your excellent article about it here.)
But your other articles here about DB2 on Mac OS X Snow Leopard, and about DB2 RoR performance, over at IBM’s website, resparked the idea of using Ruby on i5 again.

It makes me wonder if I could kill 2 birds (possibly more) with one stone.
Learn OO, Ruby, On Rails and be able to use it on Mac OS X and also i5 (using my existing skills) and other platforms.
But MacRuby is locked solid into the Mac platform. So I doubt if that is the way to go.
Also, I find it hard to find out if Ruby on i5 is in demand at all. The fact that the agencies I’m registered with do not even know about Ruby on i5, should probably give me a hint.

What would be a good approach to achieve this ?
Please, when possible, could you mention the names of specific resources, products, and development tools (used by large companies). And I’ll take it from there.
(Also, I cannot afford products like “IBM Rational Developer for Power Systems Software” and “IBM Rational Developer for i”). 😉

I hope that you have got the time for this.
Thanks in advance.

-=r