I had never anything to do with Metafont and I wonder if anyone of you could enlighten me about its actual status, importance, merits, prospects etcª in present day typographic practice.
On Wikipedia I read: “…the system has not been widely adopted by professional type designers…”;
however, it may be that someone who is dealing with special subjects or scientific editing may have some experience to share.
Type, from the very start, was created by cutting the shape from a piece of metal, where any arbitrary shape is possible, not just shapes you can make with a pen. The reason the outline-based font has prevailed with digital fonts is because it has the same kind of flexibility with regard to making shapes.
The first thing to note is that Donald Knuth is a genius, and like many geniuses, came up with brilliant ways to solve problems in different disciplines that were way ahead of their time. The problem with solving things way ahead of your time is that there's little else out there to compare with. So you make a lot of progress and you blaze a lot of trails, but you also make what look like mistakes with the benefit of hindsight. (And the problem with Donald Knuth is that he has unwittingly gathered a fanbase who cannot conceive that any of his ideas actually turn out to be mistakes.)
So DVI, TeX's page description language, was a great idea at the time but nobody uses DVI today. Instead, they used PostScript and now PDF. One of the first ways that people extended TeX was to make it use PS, and then PDF, instead of DVI. And similarly for the text encoding system, to allow the use of Unicode, and similarly for the font system, to allow the use of Type1 and eventually TTF fonts instead of METAFONTs. Knuth's fans don't like me saying this but the entire history of TeX for the past forty years has been one of replacing Knuth's trailblazing technologies with standard ones that people actually use instead.
It's not true that the METAFONT system is limited to defining glyphs based on pen shapes. You can position "left" and "right" points of an outline independently. But I think it is fair to say that most of the examples are based on tracing the centre points of a skeleton and having METAFONT fill in the left and right points, and the system does reward working in this way.
The bigger problem is that, as Knuth says himself in Digital Typography somewhere, METAFONT is essentially a constraint solving system which draws glyphs by solving simultaneous equations, and that isn't really the way that designers think about glyph drawing. Again, it's possible (as the "Nara" font example shows) to use METAFONT without the equation solving style, but again the system rewards it.
Fundamentally as a mathematician, Knuth saw type design as a problem to be solved using mathematics. I think he imagined that fonts would be made by programmers sitting down alongside designers, translating their design ideas into equations to be solved, but I think he was also realistic about how unlikely that was to happen. (And of course this was all before the widespread use of graphical user interfaces and interactive computing, so it wasn't a time when you could easily conceive of designers being the primary operators for computers.) The irony of course is that today we have font engineers who are programmers sitting down alongside designers making fonts together...
Yes, I am a Knuth fan boy . Knuth's work on Metafont/TeX was created in a era before WYSIWYG (what you see is what you get...) and GUI. It is also based around a clear separation of content vs presentation. People might be happier with fonts being outlines these days, but what's wrong with fonts being strokes, similar to hand writings? If history had gone the other way, with fonts being strokes, variable fonts (Metafont was perhaps a pioneer in that direction), text shaping - strokes connecting across glyphs - might have been implemented easier technologically, instead of the lookup-upon-lookup in opentype with outlines.
I agree some of the aproaches are evolutionarily dead ends, and outdated, from the type designer's point of view. That said, I think one should understand his work in the context that the role of "type designers" didn't/doesn't exist: making a documents/texts visually pleasing is not a very interesting work, and rather tedious, and therefore should be parameterized and automated by mathematics.
Hong-zi seems to be at http://hongzi.sourceforge.net/ , and last updated this side of the millennium, so probably will work with current metafont.
Knuth's work was largely in the 80's, so one should understand his work in that context, before WYSIWYG. Graphic terminals didn't exist, and printers were expensive shared network ones. Computer type design would involve, in those days, writing code on the text terminal to draw without seeing what it would draw, send it to a printer (often in a different room or even a different building), it coming out not quite right, go back to modifying code, send it to another network printer, which is in a different room or perhaps a different building, etc. It is tedious for sure, just walking to a different room to fetch the print-outs. No previewing on computer screen, remember?
DVI was an abstraction based on availability of network printers (and different ones!), and using cheaper or more accessible printers to preview, before sending to the expensive ones. And on-screen dvi previewers, and graphic terminals came later.
To see what curves you have drawn, in Knuth's day, you would need to send an actual print job, from your text terminal, to a shared network printer, located somewhere else, not in your room.
First version of ghostscript, came out in 1989, I think?. No on-screen previewing of postscript on screen before that, either. (At least in the open/academic world).
The printer might jam, ot off-line; go back to text terminal, re-send the print out to a different network printer, finally look at the print out, go back to the text terminal to make some changes, etc.
Repeat this process, and walking back and forth between your text terminal and the printer in the next building, 5 minutes walking/stairs etc away, a few times.
Generally speaking, those devices were referred to as "plotters" rather than printers, and before there was HPGL, there were plotters made by such firms as Calcomp, which were directed to draw lines by means of provided software libraries. However, in those days, computers usually weren't employed in type design; people drew the letters on paper, and then used a pantograph to cut metal, or had their designs photographed to make masters for phototypesetting machines.
So while the early 80s were certainly command-line based, by the latter half of the 80s things were changing. Even if it did take a little longer to reach the open source world.
"Donald Knuth started work on font creation software in 1977, and produced the first version of Metafont in 1979. Due to shortcomings in the original Metafont language, Knuth developed an entirely new Metafont system in 1984, and it is this revised system that is used today..."
I started using LaTeX (and Ghostscript, possibly, by association) between Christmas 1990 and Easter 1991. So I was a Knuth fan boy, before Apple system 7. It was on X11 on Sun OS 4 and Solaris (i.e. Sun OS 5). OSF and CDE came a few years later, so it was probably one of X11 openlook, mwm or fvwm1. I seem to remember being able to switch between those 3 window managers, or at least those widget sets.
More likely, he had a Sun Sparc / DEC / IBM machines in the 198x's (I call that the 90's), or had shared usage of one. By IBM, I don't mean "IBM-compatible PCs", but one of the other sorts...