A little note on the history.

doc/Design Goals.md

@@ -25,3 +25,28 @@ to spend a lot of time debugging.
 
 The intent is not to make it absolutely impossible to make such errors,
 just harder.
+
+### Some Background ###
+
+The ideas in SixtyPical came from a couple of places.
+
+One major impetus was when I was working on [Shelta][], trying to cram
+all that code for that compiler into 512 bytes.  This involved looking
+at the x86 registers and thinking hard about which ones were preserved
+when (and which ones weren't) and making the best use of that.  And
+while doing that, one thing that came to mind was: I Bet The Assembler
+Could Track This.
+
+Another influence was around 2007 when "Typed Assembly Language" (and
+"Proof Carrying Code") were all the rage.  I haven't heard about them
+in a while, so I guess they turned out to be research fads?  But for a
+while there, it was all Necula, Necula, Necula.  Anyway, I remember at
+the time looking into TAL and expecting to find something that matched
+the impression I had pre-formulated about what a "Typed Assembly"
+might be like.  And finding that it didn't match my vision very well.
+
+I don't actually remember what TAL seemed like to me at the time, but
+what I had in mind was more like SixtyPical.
+
+(I'll also write something about abstract interpretation here at some
+point, hopefully.)