[tex-live] Having a .fmt for different engines

[Taco Hoekwater]

Gerben Wierda wrote:
> 
> My personal preference is a change in ConTeXt. For ConTeXt, with its 
> separate texexec/texmfstart calling mechanism the engine is a variable 
> (but this is not reflected in the name of the formats). For XeTeX and 
> PDFTeX, the engine is a start and the macro set (Plain, LaTeX, etc.) is 
> a variable leading to variable format names.

The format names used to be different, thanks to the different
extension used by the various engines. This feature was removed
for web2c in favour of $engine, but support for that was never
implemented in the tetex/texlive tools, resulting in suddenly
identical filenames.  Don't go blaming context for that!

Taco