Update readme

README.md

@@ -1,8 +1,61 @@
-# incless
+# Incless: a portable and extensible Common Lisp printer implemetation
 
-This project implements print-object methods for many standard classes.
+This project implements `print-object` methods for many standard
+classes and provides the interface to `write`, `print`, etc.
 
-## License
+# Requirements
 
-MIT
+[ABCL][], [Clasp][], [ECL][], and [SBCL][] is the only current
+implementations that this system has been tested on. 
+
+In addition to a clone of this repository in a location that is
+discoverable by ASDF you will also need a clone of
+[trivial-stream-column][].  Incless does not implement pretty printing
+or `format`. These systems are implemented by [Inravina][] and
+[Invistra][] which work in coordination with Incless.
+
+# Usage
+
+The core functionality is in the `incless` package, but the Common
+Lisp-like interface of `write` and `print-object` is in the
+`invistra-extrinsic` package and system. To call write try the
+following in SBCL:
+
+```
+* (asdf:load-system :incless-extrinsic)
+T
+* (incless-extrinsic:write :wibble)
+:WIBBLE
+NIL
+```
+
+Incless can be loaded along with Inravina and Invistra to provide a
+printer, pretty printer, and format. To load the complete stack try
+the following:
+
+```
+* (asdf:load-system :invistra-extrinsic)
+T
+* (incless-extrinsic:pprint '(loop for i in '(a b c) 
+                                    unless (eq i b) do (stuff i) (quux i) and collect i))
+
+(LOOP FOR I IN '(A B C)
+      UNLESS (EQ I B)
+        DO (STUFF I)
+           (QUUX I)
+        AND COLLECT I)
+* (invistra-extrinsic:format t "Wibble: ~a~%"
+                             :quux)
+Wibble: QUUX
+NIL
+```
+
+[ABCL]: https://armedbear.common-lisp.dev/
+[CLASP]: https://github.com/clasp-developers/clasp
+[ECL]: https://ecl.common-lisp.dev/
+[Inravina]: https://github.com/s-expressionists/Inravina
+[Invistra]: https://github.com/s-expressionists/Invistra
+[SBCL]: http://sbcl.org
+[SICL]: https://github.com/robert-strandh/SICL
+[trivial-stream-column]: https://github.com/yitzchak/trivial-stream-column