SlateAn object-oriented programming language based on Smalltalk syntax, prototype-based object system, and multi-method dispatch, by Brian T. Rice and Lee Salzman. The intent is to provide an intermediate porting platform for the TUNES Project.
The home page has most of the available documentation. The code is available via CVS.
Note: The name Slate was originally used to name a "object-oriented and purely functional, Forth/Self/Beta/Lisp hybrid with no syntax", which was intended to be a TUNES HLL (or HLL-) candidate. This project was eventually abandoned. The name was then recycled for the language (by the same authors) currently known as Slate. This current Slate language is not at all intended to be able to function as a HLL for Tunes; it probably doesn't even want to be directly associated with Tunes. In spite of this, it might anyway, when completed, loosely speaking be able to give some a little bit more concrete finger-pointings to some Tunes features than has previously existed, since it aims to be a refinement of the nicest things in the Self/Squeak/Lisp-machine tradition.
For those who eventually for some kind of reason would be interested in the "original" Slate language: the information that is available exists scattered in mailing lists archives and tunes channel chat logs from around something of the years 2000-2001