Am 26.12.2013 um 23:18 schrieb Rudolf Bahr <quasi@quasi.de>:

> On Thu, Dec 26, 2013 at 08:49:30PM +0100, Wolfgang Schuster wrote:
>> 
>> Have you tried the unifraktur fonts, as you can see on the website the font has features to change
>> the umlauts and also to replace the normal s with the long s.
>> 
>> \definefontfamily[mainface][rm][Unifraktur Maguntia]
>> 
>> \setupbodyfont[mainface]
>> 
>> \definefontfeature [longs]     [cv11=yes]
>> \definefontfeature [diaeresis] [cv15=yes]
>> 
>> \mainlanguage[de]
>> 
>> \starttext
>> 
>> \input knuth
>> 
>> schönstes – {\feature[+][longs]schönstes}
>> 
>> ſchön Üben – {\feature[+][diaeresis]ſchön Üben}
>> 
>> \quotation{Quoted text}
>> 
>> \stoptext
>> 
>> Wolfgang
> 
> 
> This is the answer of my context (version: 2013.05.28 00:36):
> 
> l.2 \definefontfamily
>                   [mainface][rm][Unifraktur Maguntia]
> ? h
> The control sequence at the end of the top line
> of your error message was never \def'ed. If you have …

Replace the \definefontfamily line with

  \definetypeface [mainface] [rm] [specserif] [Unifraktur Maguntia] [default]

because the new font command was added last autumn and your TeXLive installation
uses a older context version (not sure if the \feature command exists there).

> I don't know, whether there apply in English texts the same rules as in German ones with respect 
> to Fraktur or similar fonts.
> The written Knuth text (in the .pdf-file) would contain some right "s" at end of words and syllabs 
> as in "Thus", "components", "activities" or the third "s" in successfull, but the rest of all the 
> other "s" would be wrong. 

What do you expect from a text with doesn’t contain any long s in the input.

Maybe your expecting from context to make the right choice for the s but there
are cases where you won’t get the correct output and manual correction
is necessary.

Wolfgang