I believe you have two different requirements. The first is for
an infratructure of distributed agent technology. That is, the ability
to have programs talk to each other (and maybe "visit" each other)
around the Internet. The second requirement is specific to the use
of such an infrastructure, for doing 'collaborative' or 'social' filtering
or the like.
With regard to the former, there has been development of a derivative
of TCL, called safe-tcl, to allow tcl code to visit remote locations without
danger to the executing host. While this has been done in the context
of email, it will apply to other situations, and the Web seems a perfect
candidate. (Since safe-tcl has been folded into Mime, folding it into
the Web ought to be quite straightforward.)
You can join the safe-tcl discussion by sending mail to:
safe-tcl-request@CS.UTK.EDU
Openly-available specifications and software which implements safe-tcl can
be obtained from:
ftp.ics.uci.edu:/mrose/safe-tcl
It was developed by Marshall Rose and Nathaniel Borenstein.
Dave Crocker