You could find a lot of information at
VPRI wiki. There is the "Text Field Spec for LObjects" project, which was announced in 2010 here:
http://www.mail-archive.com/fonc@vpri.org/msg01279.html, basing on the "Mochi" system, as Ted Kaehler said: "It has many half-finished experiments in it, and a fair amount of just plain wreckage". Although there are many of working OMeta's examples for Squeak (ForAll language, SpecParser, Nile), Worlds are also presented there and it is an updatable image. Another is
Yoshiki's SqueakBootStrapper image with BootStrapEncoder/parser and of course:
OMeta/JS wiki.
Now thinking, that we need to ask the VPRI team for official permission on using and experimenting with these stuff in Squeak, especially concerning to the image side parts of "Mochi" system. Bert, may be you could bring some clearance on this, please?