Cells is a mature, stable extension to CLOS that allows you to
create classes, the instances of which have slots whose values are
determined by a formula. Think of the slots as cells in a
spreadsheet (get it?), and you've got the right idea. You can use any
arbitrary Common Lisp expression to specify the value of a cell. The
Cells system takes care of tracking dependencies among cells, and
propagating values. It is distributed under an MIT-style license.
There are still some resources over at the old Cells
homepage at Kenny Tilton's tilton-technology.com site.
The Cells-Gtk project is a Cells-based
wrapper for the Gtk GUI toolkit, developed originally by Vasilis
Margioulas.
The Cello project is a Cells-based,
portable GUI toolkit. It is currently in a prerelease state, and for
now has been brought under this Cells project for support and any new
development.
If your Lisp system has
asdf-install, you can install Cells with the following command:
(asdf-install:install :cells)
Otherwise, download the distribution from here
and follow the instructions in README.
For now, just the stuff you can find on the original Cells home page
here.
You can browse the CVS repository of Cells-Gtk code
here.
The repository of all other Cells code (including Cello) is
here.
In there you will find the Cells code itself
here, which also requires Kenny's favorite CL utilities found
here.