I am using a graphical programming language that has 2 approaches to constraints for text layout : one you get to tinker about in an API, one you get to request layout for text/font/font_attribs and you accept the results ( the Alan Knight O-O no-internals-SVP version ? )
A pythonic quasi-logic language with minimalist constraints for Unicode text is under development in UK ; I am alpha testing one such non-graphical prgrm'g lang for Unicode text-only from USA, but it is NOT cross platform oddly enough; Logtalk + swi-prolog also has constraints handling ;�� typed-Prolog AKA Mercury gen's C or Erlang ; Oz has gone quiet since 1.4 and Lively Kernel ?�� I have lost track of Croquet.�� User-friendly Scheme is now called Racket, btw.�� And "Claire", the lang ? Alice ?
[ by way of explanation : this Monday is a bank-holiday here, but the nearest beaches have ice piled on them and its some other holiday in USA ; now for morning java ( as in coffee ) ]�� Isn't "brackets" some editor project ?