TeXtrace, originally developed by Péter Szabó,
is a bundle of Unix scripts that use Martin Weber's freeware
boundary tracing package autotrace
to generate Type 1 outline fonts from MetaFont bitmap font outputs.
The result is unlikely ever to be of the quality of the commercially-produced Type 1 font,
but there's always the FontForge font
editor to tidy things. Whatever, there remain fonts which many people find useful
and which fail to attract the paid experts, and auto-tracing is providing a useful service here.
Notable sets of fonts generated using TeXtrace are Péter Szabó's own
EC/TC font set tt2001 and Vladimir Volovich's CM-Super set,
which covers the EC, TC, and the Cyrillic LH font sets (for details of both of which sets,
see "8-bit" type 1 fonts).
Another system, which arrived slightly later, is
mftrace:
this is a small Python program that does the same job.
Mftrace may use either autotrace (like TeXtrace)
or Peter Selinger's potrace
to produce the initial outlines to process. Mftrace is said to be
more flexible, and easier to use, than is TeXtrace, but both systems
are increasingly being used to provide Type 1 fonts to the public domain.
The MetaType1 system aims to use MetaFont font sources, by way
of MetaPost and a bunch of scripts and so on, to produce high-quality
Type 1 fonts. The first results, the Latin Modern fonts,
are now well-established, and a bunch of existing designs have been reworked
in MetaType1 format.
Mf2pt1 is another translator of MetaFont font sources by way of
MetaPost; in addition, available, mf2pt1 will use
Fontforge (if it's
available) to auto-hint the result of its conversion
(Mf2pt1 is also written in perl).