As I recall, it's not a ROM in the conventional sense. The one showing ICS was running within a chroot. A Russian dev was using the app chroid that was being tinkered with over on the Chinese site treo8. Performance was stuttery at best. There was an article here on the site about it, linked elsewhere in this thread.
Originally Posted by palmpreandroid
This dev was also going to be quite busy over the next month or two and said he didn't have time to so much as upload the source he'd been using to get this running as his current approach was very sloppy. Would love to see it myself.
I'm not at all an expert on building Linux code, but I recently looked through all the various Android on webOS hardware attempts. It's a real PITA when you don't have driver source. I'd have tried my hand at a few things if there was even a reasonable way to start. Unfortunately almost all of these projects suffered from people not providing sufficient (or any) source code. Where there *is* source code, instructions on how to properly reconfigure, compile and install are scarce. Makes sense since each project (Veer, Touchpad, Pre) was probably thought as a one-off. Once the ground work was laid, the details on how it was accomplished got hard to find. People weren't repeating the effort over and over, like they do with Android devices which all have more in common.
Just trying to create a boot environment that doesn't risk destroying the handset was frustrating. Boot from NFS (used for Pre) was most appealing for testing purposes, but misc documentation for compiling uImages seemed conflicting. Likewise with moboot: looks like an awesome tool that should work on all the webOS devices to me. Can't find any clear documentation on how to configure it for other devices, though. (Just need to adjust kernel settings, or does the moboot image need readdressing per device? How were those found for the Touchpad or Veer?) Finally there's the chroot approach as was done here. That's not very appealing long term, however, as it's likely to continue suffering performance issues.
Anyway, those are my failed thoughts. Take it all with a grain of salt. I'm kind of an ***** with this stuff.