The Concrete Roman fonts were designed by Don Knuth for a book called
"Concrete Mathematics", which he wrote with Graham and Patashnik
(the Patashnik, of BibTeX fame). Knuth
only designed text fonts, since the book used the Euler fonts for
mathematics. The book was typeset using Plain TeX, of course, with
additional macros that may be viewed in a file gkpmac.tex,
which is available on CTAN. A few years later, Ulrik Vieth
designed the Concrete Math fonts. The packages beton,
concmath, and ccfonts are LaTeX packages that
change the default text fonts from Computer Modern to Concrete.
Packages beton and ccfonts slightly increase
the default value of \baselineskip to account for the rather
heavier weight of the Concrete fonts. Packages
concmath, and ccfonts also change the default math
fonts from Computer Modern to Concrete and use the Concrete versions
of the AMS fonts (this last behaviour is optional in the case
of the concmath package).
There are no bold Concrete fonts, but it is generally accepted that
the Computer Modern Sans Serif demibold condensed fonts are an
adequate substitute. If you are using concmath or
ccfonts and you want to follow this suggestion, then use the
package with boldsans class option (in spite of the fact
that the concmath documentation calls it
sansbold class option). If you are using beton,
add \renewcommand{ to the preamble of
your document.
\bfdefault}{sbc}
Type 1 versions of the fonts are available. For the OT1 encoding, they are available from MicroPress. The CM-Super fonts contain Type 1 versions of the Concrete fonts in the T1 encoding.