Joe Strout: The first line on their site says "This program will allow you to generate bitmap fonts from TrueType fonts." So there - really not much of a common denominator.
Though there are some ?tag=ttf fonts in collection here from the past, I think I am actually against adding other vector fonts here now. Those two worlds (of pixelated and vector graphics) have little in common, imo.
There is a library and an editor I wrote in Lazarus, as
of tools there's https://github.com/crs2/Bmf/blob/develop/ttf2png.php and https://bmf.php5.cz/img2bmf.php

I've recently become aware of the "BMFont" format, popularized by AngelCode.com (http://www.angelcode.com/products/bmfont/). It seems to be essentially the same as BMF, except that it uses two files: a PNG file for the glyph data, and a separate text file with the metadata. That's two files to keep track of instead of one, but it has the advantage that you can easily look at the PNG file for a preview of the font.

Any thoughts about how these two formats relate? Are there conversion tools from one to the other? Finally, one reason I've heard that people like BMFont is that there is a nice (Windows) tool for creating them from TrueType fonts -- do we have such a tool for BMF? (Except for mine, which I have not released?)

Thanks a lot for the super quick update on the UI.
Soooo much better now.

Oliver: I added this project to the ?page=support.

I have finished a bmf2bdf converter:
Features
- Convert .bmf to .bdf
- Converts DOS codepage to Unicode (-u option)
- Convert monospaced proportional font back to none-monospaced font (-p)
- Optional glyph spacing with -x
- Optional baseline adjustment with -y
- Brightness threshold with -l for multicolor fonts
- Generated BDF can be modified with gbdfed and FontForge
URL: https://github.com/olikraus/u8g2/tree/master/tools/font/bmf2bdf
The converter is a single .c file without other dependencies. Windows exe is included in the above folder.

Let me add some generic notes from my tests with the bmf2bdf converter:
1) Some fonts are marked as monospaced, but are actually proportional fonts.
2) The baseline seems to be shifted for some fonts (ok, it depends on the definition of baseline). But the problem is: The above bdf converter can't fix this: If the uppercase A is not placed on the baseline, then this is also not the case for the generated BDF.

Again, thanks for the effort and improvements for the filter.

@Oliver, @Joe: Allright, I hear ya. Did some changes to address this, added inputs to filter the number of colors and characters in the font. Yeah, the number of characters is not exactly the same as filtering whether the font has a lower case letters, I hope it'll be good enough for now, though.
Btw. you can still sort the search result by the number of colors in the font, as well as the number of characters in it. Also, you can filter just the fonts with ?tag=incomplete-alphabet.

I think Oliver makes good points. I also think it'd be great to be able to filter by number of characters in the font. Say I put in 64, it should show only fonts with 64 characters or more. Right now there's no good way to find more complete fonts.

Thanks for all the effort here. Great work.
While looking around here and exploring all the nice fonts I also was thinking about some improvements:
1. Seeing the full charset requires two clicks. What about removing the full charset expander and just keep the "load" button?
2. A filter for single and multi color fonts would be great
3. A filter for fonts with and without lower case chars would be also nice.
Thanks again.

I've found three Font Collections by Exile and will be adding font converted from pictures in those collections.
Unless there's any note in the picture, there's no telling about the name of the font or its author, so I guess I will have to set some name and maybe later, upon knowing more, renaming each.

I'm working on a GUI font editor for the BMF format (versions 1.1 and 1.2). This will be free and open-source. I have a decent start on it, but I am always short on time, so I'm trying a bounty system (bountysource.com) to recruit some help.

If you think a graphical BMF font editor would be useful, please consider chipping in a few bucks to the first bounty task:
https://app.bountysource.com/issues/111282532-feature-add-glyph-selection-to-fontedit

Or, if you want to learn MiniScript and Mini Micro (these are easy and fun!), you could tackle the task yourself and collect the reward!