To give a curmudgeonly viewpoint, here's what <i>doesn't</i> excite me about RubyMotion: it's for iOS.<p>As a Rubyist, my entire toolchain, from text editor to interpreter to production server, is open source. I use and create open-source gems. My media is the open web, and many of my users are on open-source browsers. I love this.<p>So while I'm generally a fan of any clever technology, I'm not keen to see my fellow developers lured into developing on proprietary platforms.<p>Yes, this is a rather zealous point of view. But as Mr. Ballmer famously reminded us, the success of a platform depends on developers. And I'm rooting for open platforms.